The Science of Stir-Fry with J. Kenji López-Alt | Christopher Kimball’s Milk Street

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Episode 606
March 4, 2022

The Science of Stir-Fry with J. Kenji López-Alt

The Science of Stir-Fry with J. Kenji López-Alt

J. Kenji López-Alt gives us a lesson on Wok 101 and reveals the science behind great stir-fry. Plus, Cheryl Day joins Christopher Kimball to tackle your baking questions about everything from powdered milk to cardamom buns; cookbook author Chelsea Monroe-Cassel explores the food of “Game of Thrones” and “Star Wars”; and we visit Morocco’s communal bakeries to learn an all-purpose flatbread recipe.

Questions in this episode:

"Can I use powdered milk as a replacement for liquid milk in a recipe?"

"I tried your Chèvre Cheesecake with Black Pepper recipe. I’ve never had so much go so wrong and taste so good."

"I made your Swedish Cardamom Buns recipe. Unfortunately, my fiancé doesn't like cardamom. What can I substitute for the cardamom and what ratios could I use?"

"I have a ceramic bundt pan that I have had for a long time. My cakes will stick to it. So do I need to get rid of it?"

    J kenji

    Chris Kimball: This is Milk Street Radio from PRX. I'm your host Christopher Kimball. Today J Kenji Lopez Alt gives us a wok cooking lesson for home cooks, including the science of stir frying and wok hei the distinctive flavors and aromas often referred to as the breath of the wok.

    J Kenji-Lopez Alt: My dad was obsessed with Chinese food and so we would spend weekends going around Chinatown then the thing that he always particularly liked was when the chou fung had that nice smoky flavor like it that was all that was always the refrain at hear my head. Like we would go to places like, oh yeah, this is like great chou fung it has that nice smoky flavor. And it was something that I heavily associated just with restaurants. It wasn't something that even when we tried to make chocolate at home, it wasn't something that we ever really got at home.

    CK: Also coming up with learn about Morocco's communal bread ovens, and Cheryl Day me to answer your baking questions. But first is my interview with Chelsea Monroe-Cassel about making fantasy foods a reality. She's the author behind A Feast of Ice and Fire, a Game of Thrones Cookbook, along with seven other cookbooks based on the foods of fantasy fiction. Chelsea, welcome to Milk Street.

    Chelsea Monroe-Cassel: Hey, thanks for having me.

    CK: You think a lot about how authors treat food in their novels? (CMC: Yes). So maybe give me a couple examples where you found the food really exceptional?

    CC: Sure. Well, it's definitely an occupational hazard for me that I am always focused on any food reference going through books, even movies, TV shows, video games. It's like I can't unsee it now, for better or worse. And I think my go to example for doing it very well is George RR Martin, with whom I worked on the Game of Thrones cookbook is food descriptions are so lavish. And so, part of the books and part of that world that it's sort of an inside joke with fans of his work. Everything's dripping in bacon grease, and the lemon cakes are always being stolen from the kitchens and things like that. But I think it works so well, because he's really thought about where these things come from in the world, and how people are getting them and what it means to someone in, say, Winterfell to have sweet pastry made out of lemons, which can't grow anywhere in the north, so they have to be imported and are really a special treat.

    CK: Well, I think you also wrote about the fact that Winterfell’s menus are very different than the South. (Absolutely) Food described where you were

    CC: exactly. And it very much characterizes the different regions. And I love when an author goes through the effort of thinking through a lot of that, because it obviously makes my job much easier when it comes to translating those descriptions into real food. Because I have a source then for, you know, the trade routes or growing seasons, or what spices might be used in different places.

    CK: You got started by doing a fan blog, right?

    CC: I did. Yeah. A friend of mine, Syrian, who's my coauthor on the Game of Thrones cookbook. She and I were roommates in Boston. And we are both reading the books or rereading them and this is before the show came out. And we decided we would make dinner as something from the books. And at this point, there were no recipes for any Game of Thrones food online, which is sort of hard to imagine now. We thought, well, if we're looking for recipes, maybe someone else is also so we'll just throw it up on a blog.

    CK: You talk about sourcing medieval recipes, especially for something like Game of Thrones. Why medieval? Because the style of cooking. I mean, I guess Game of Thrones is medieval at heart. Is that why?

    CC: Yeah. And I think it's very interesting to explore the historical recipes in large part medieval but also Elizabethan and even back to ancient Roman because in a way it does what good fictional food also does it takes something familiar and defamiliarizes it because it's the same ingredients, you know, it's chicken and oregano and cinnamon, but combined in such a way that you've maybe never tried before.

    CK: I've done a little bit of cooking out of 19th century American cookbooks but you're going back a few more centuries. And you talked about swans, and you said the best I could find was an online source that would deliver a live and presumably very angry swan for about $1,000. (Yeah) So are there other ingredients, let's say for this book Game of Thrones, that would be a good substitute for some of the things you needed to use.

    CC: Well, not so much substitutes. There were some things that were just off the list because we couldn't source them. When we were really going gung-ho, we were looking for Lamprey, which I think you can get around the Great Lakes. But we asked several befuddled, fishmongers who couldn't really understand why anybody would want them. But I think one of the interesting things was sort of discovering ingredients that have fallen out of fashion. A lot of spices in particular.

    CK: Like what kind of spices?

    CC: Grains of Paradise is a personal favorite. And it it seems somewhat of a resurgence now homebrewers use it a lot

    CK: Isn't it used a lot in West Africa, too, isn't it?

    CC: It is yes and that's I believe, where it originates, but it was a precursor to our black pepper. And it's just so much more interesting and nuanced and tingly on the tongue. And I think it's really fabulous. It's, I've got some of that just in my pepper grinder at home.

    CK: So, your recipes, you give two versions, you know, you do sort of the the authentic one, and then you do a modernized version. But the recipes I'm looking at a breakfast in King's Landing right now. You know, cheese and onion pie, white beans and bacon, quails and butter, apricot tarts, peaches and honey, sweet corn fritters. The menu sounds, you know, pretty reasonable. I mean, if you if you said I'm doing a cookbook on Game of Thrones, I'm going like, okay, there's going to be dragon confit or something in here, but it's quite manageable, right?

    CC: It is and that is always one of my goals. I want people to actually be able to make it I don't want it to just be some novelty coffee table item.

    CK: You mentioned lemon cakes. Are those individual cakes? Are they big cakes what are lemon cakes?

    CC: They are. I think in at least one place they described as snitchable like something that you could sneak off a tray. And so, the historical recipe is really more like a cookie. But the modern recipe is little petit four squares, which are altogether too easy to eat.

    CK: So, let's move on to Star Wars, The Star Wars Galaxy Edge Cookbook. A couple things stood out to me. The Mustafarian Lava buns the planet Mustafa it's a magma covered world.

    CC: It is that's where Anakin and Obi-Wan have their last fight. One of my personal favorites is the Munch fungus loaf.

    CK: What is a munch fungus loaf?

    CC: It's sort of a curried mushroom bread. And it's it's very interesting. I did not think I would like it but it's a nice with a little butter toasted.

    CK: Almost everything's good with a little butter toasted and that's including hotties slime pods. I think you made gnocchi in green sauce. That was your version

    CC: I did Yeah, with the avocado pesto. So, it's it's bright, vibrant green, but they look like little grubs almost swimming around in it. It tastes much better than it looks, I have to say.

    CK: So, you spent years doing this and dive deeply into these books. Do you get to the point where it's almost real to you and that is the these worlds like George Martin, these worlds are so brilliantly described that they become almost as real as medieval times were here on earth?

    CC: In a few rare situations. I think that that definitely does happen. And I think George Martin's books are definitely one of them. Any world where you can spend that much time thinking about it and puzzling it over is one that hopefully leaves a lot of room for exploring in other ways, and food is one of those.

    CK: Chelsea, it's been a pleasure a tour of great books of fiction and their recipes. Thank you.

    CC: My pleasure. Thanks so much for having me.

    CK: That was Chelsea Monroe-Castle, author of A Feast of Ice and Fire, her 9th book The Star Trek Cookbook comes out this summer. Right now, Cheryl Day is here to answer some of your baking questions. Cheryl is the owner of Back in the Day Bakery in Savannah, Georgia. She's also the author of Cheryl Days Treasury of Southern Baking. Cheryl, when you were starting out with Back in the Day bakery, you told me that one of the things you did was bring some of your baked goods to the local barber shop that was nearby.

    Cheryl Day: Yes

    CK: to sort of warm people up

    CD: Boys to men.

    CK: Is the barber shop I think the barber shop still there, isn’t it?

    CD: Oh my gosh. It's still there. Yeah, we've been open 20 years. It's been there over 30 years and they really did love when they would see me coming across the street with baked goods.

    CK: And so, you just dropped them off and introduced yourself and

    CD: Dropped him off introduced myself, Griff actually used to go get his haircut over there, too. And we just really wanted the folks in our neighborhood to know we wanted to be a part of the community. And that was one way that we thought we could do it. And we also selfishly knew that once they tasted our cinnamon buns and our biscuits, that they would be back. And it worked. I mean, how could you not?

    CK: Okay, Cheryl, it's time to take some calls.

    CD: Let's do it.

    CK: Welcome to Milk Street who's calling?

    Caller: This is Dan from San Diego.

    CD: Hey, Dan,

    CK: How can we help you?

    Caller: So, I have a question about milk. When you use milk and baking a cake or whatever I do. A lot of recipes call for milk. Ever keep nothing that I don't drink it, I don't use it much. So, I've always wondered if that I could use powdered milk as a replacement for just normal liquid milk bought from the store?

    CK: Yeah, I keep a little carton of powdered buttermilk in my fridge at all times. And I think the formula would be the same for regular powdered milk. So, if the recipe calls for a cup of milk, you'd substitute one cup of water, the same amount, and then a quarter as much of the powdered milk or butter milk. So, a recipe that calls for one cup of milk, use a cup of water plus a quarter cup of powdered milk. And that should do it. And it works pretty well. And maybe Cheryl can talk about this too. I do know that some people use powdered milk as a secret addition.

    CD: Absolutely.

    CK: Yeah, there you go. Yeah, there you go. Cheryl, take it from here.

    CD: It’s definitely a secret in the baking world. So, it's great that you're thinking of substituting it because then you'll always have that milk powder in your pantry, you know, whenever you want to start baking. But the secret way that we use it is about a tablespoon goes into cookie doughs and brownies. And it really adds a depth of flavor that is hard to describe. But it is definitely a secret, magical ingredient for baking. So, you might want to give that a try also, since you'll have it on hand.

    CK: And you can also toast it in a skillet, or you know, small skill in like a nonstick skillet or something.

    CD: Yeah, I love doing that. That adds a really great, like a nutty kind of flavor to doughs.

    Caller: Using the powdered milk isn't going to change in a major way that consistency or how the recipe work?

    CD: No, it actually won't change at all. It'll be exactly cup for cup if you're using it in a recipe that calls for fresh milk. But again, this other little secret is you'll add the powder and that doesn't change the ratio at all. It just adds a little bit of fat and a little bit of flavor without changing the moisture content.

    Caller: Sweet. Cool. Perfect.

    CD: All right, great thanks for your question.

    CK: You know that this was a good one. Dan, thank you so much for calling.

    Caller: Thanks. Have a good afternoon.

    CK: Take care. This is Milk Street Radio if you want to become a better baker give us a ring 855-426-9843 Once again 855-426-9843 Or simply email us at questions at Milk Street Welcome to Milk Street who's calling?

    Caller: This is Sharon Peritus.

    CK: How are you and where are you calling from?

    Caller: Eastern Washington State.

    CD: Hi,

    CK: How can we help you?

    Caller: We did your goat cheese cheesecake recipe. The one with the black pepper and that graham cracker crust. I've never had anything go so wrong and tastes so great. It was it was a dilemma. I followed your instructions. I think literally to the letter. The last step is to add the eggs. And so, I did all of that added the two yolks put the bowl that I'd had the eggs in into the sink and looked back and the entire thing was curdled. No idea why put it in the oven followed those directions. When I pulled it out. there was like oil almost looked like clarified butter all over the pan that I baked it on. We cut the cake and it was heavy. You could see some curdling, but it tasted wonderful.

    CK: This curdling usually happens because There's some ingredients that are too cold, the chevre, the cream cheese, the cream fresh all that stuff, the eggs,

    Caller: everything had been at room temperature. I had it out for several hours.

    CK: I do have one other suggestion and then I'll let the expert speak here, Cheryl. Usually, what people do wrong with this is they don't whip enough or beat enough when they they add the eggs. I was taught a long time ago to wait actually 15 to 20 seconds between adding each egg. Because you really want to create the right structure. Yeah, Incorporate it so it just sounds to me like you didn't take enough time. I mean, Cheryl, what do you think?

    CD: I would probably agree with that. I'm a little curious about where this clarified butter situation is happening from. Is there butter in the recipe?

    CK: There is, well there is just well there is for the crust,

    CD: just the crust,

    Caller: but that's it and the crust stayed fine.

    CK: One thing though, sometimes you're doing a batter, it can look a little curdled. (CD: Right) but when it bakes, it's fine. (CD: Exactly) yeah. But in this case, unfortunately it wasn't fine. So, I'll still stick to the egg thing.

    CD: But yeah, maybe it just needed a little bit longer. Did you try to remix it or you just kind of poured it in at that point.

    Caller: I let it mix for a while to see if it would come back. But not a terribly long time.

    CK: Well, you know, you should do you should actually get a little timer because 20 seconds just feels like forever.

    CD: It does.

    CK: And usually people do it for four or five seconds. Now the next thing so just make sure, because I think that would definitely help.

    CD: And if you think about it, what happened even if you're trying to mix it after it already broke. It's almost too late at that point. But when you're incorporating it, that's when you want to make sure that it's mixed.

    Caller: to incorporate it yeah,

    CK: Exactly.

    CD: All right.

    Caller: Well, thank you so much. I appreciate you taking the time with me.

    Caller: Oh, thanks for your question.

    CK: Thanks for calling.

    Caller: All right, take care. Bye bye.

    CK: You’re listening to Milk Street Radio. Up next J Kenji Lopez Alt gives us a wok cooking lesson. That's right up after the break. This is Milk Street Radio. I'm your host, Christopher Kimball. Right now, it's my interview with J Kenji Lopez Alt about his latest book, The Wok. Kenji, welcome back to Milk Street.

    JKA: Thank you. Thank you for having me.

    CK: You know, I'm fascinated by the wok. I think we talked about this when I was in Taipei a few years ago, I watched someone fry, steam, stir fry, do all these things, you know, within a space of a few minutes in the same wok in I do think it's the ultimate cooking vessel. But let's start at the very beginning you said originally, it was something used for holding or drying grains, right. It wasn't even used for cooking.

    JKA: Yeah, I mean, the history of the wok goes back, I don't remember which which dynasty it was. But right around zero ad was right around when the one walk started showing up. And they were originally made out of stone or clay and used as giant vessels for drying grain. And eventually as as metals and other materials started being used, they became much more versatile. So when cast iron came around, and people started making woks out of cast iron, you could then sear and fry and sizzle and do all these other things on woks. And of course, modern woks, most of the time these days are made of a carbon steel, which is even more versatile than cast iron, because it's not as brittle. And it's lighter. So, you can do things like stir fry very effectively in them. But yeah, the original walks were sort of fixed in place, big things that were used to dry grains.

    CK: So that let's start with the biggest concern slash problem, which is, if you're not in a restaurant, and you don't have, you know, one of these massive burners, right, you just don't have the same amount of heat output in a home kitchen. Which means that you effectively, some people would argue, can't really stir fry, or use a wok because you don't have enough heat. Now you're going to disagree with this. But I I'd love to hear the answer because this has been bugging me for 20 years.

    JKA: I'm going yeah, I am going to disagree with it. So, the first and easiest answer for that is that the vast majority of people in the world who cooked with woks like we're talking hundreds of millions of people cooking in a wok every day, don't have a restaurant style burner at their house. Right. So, there are you know, people who are cooking for their whole families on regular home burners throughout Asia. And of course, you know, scattered around the world as well. So, the idea that that cooking in a wok requires this 150,000 BTU restaurant burners is sort of silly, right? You know, I think I think a lot of that is colored by our experience as Americans were most of our exposure to Chinese food is restaurant style Chinese food, you know, so like for me, I grew up in New York and we grew up eating Cantonese and Hong Kong inspired Chinese American food in Chinatown, right, and so dishes like Beef Chow Fun, right? So that would be one of those quintessential dishes that really has that strong wok hei, that smoky flavor that really requires a very strong Restaurant Style burner. But there's an entire wealth of home cooking, that you don't necessarily find them. Right. You know, of course, there is some overlap between home cooking your restaurant cooking, but there's a lot of stuff that is cooked at home that you wouldn't necessarily find on a restaurant menu.

    CK: So just so I understand wok hei, is that very smoky aroma really, and flavor you get from wok cooking. And usually we're talking about a high heat burner in a restaurant. But I think what you're saying is, you can still get some wok hei at home without a high heat burner, by using different kinds of recipes and different techniques, but not by trying to replicate how someone cooks with a walk in a restaurant, right?

    JKA: Yeah, exactly. I think you know, it's sort of like saying, I can't cook a steak the way they cook it at Peter Luger, because I don't have a 1600-degree broiler at home, right and but when you cook a steak at home, there are other ways you can cook steak at home that are equally delicious. They're just different, right? You know, so home cooking and restaurant cooking are just two different types of cooking.

    CK: Let's pull a real Kenji. (Okay) and let's do the science of these oscillations in a stir fry. I thought this is really interesting. So, take us briefly through the science of stir fry.

    JKA: Okay, so there's a few steps in stir frying and, and honestly, stir frying is a misnomer. For the actual term, it's really much more of a toss frying. So, you're not, you know, stir frying to me gives you the idea that you're sort of leaving the wok in place, and you're stirring it around with a spatula, which is not really what you're doing. With stir frying, most of the action comes from shaking the wok, as opposed to shaking the tool that's in there, there was a study done where this team went out and took some slow-motion video of people cooking in woks, to really sort of break down the motion and understand what's going on. And what they found is that there's basically four steps, you know, so that you initially start with a wok flat on the burner, but a little bit angled up so tilted towards the back. And then you start to kind of push the wok forward, and then you flip the food up over the other side. And then you let it roll back and kind of a wave over the back of the wok and catch it near the handle before you start repeating that process again. So that motion is really essential to stir fry, because it does a couple things. So first of all, you're keeping the food constantly moving. And when you're working with small pieces of food, keeping it constantly moving is going to make sure that it all cooks evenly. Secondly, you're throwing the food up. And if you're using a gas burner, or you have properly preheated everything, there's this kind of hot column of air that moves up the back of the wok as you pull it forward. And your food kind of flies up through that hot column of air. And that allows the steam that have been generated by the food in the wok. It's trapped in that column of air. And when you throw the food back through it, the steam condenses on the food. And that action of condensing actually transfers energy to the food. And so, what it does is that stirring and tossing process cooks your food much faster than just sort of letting it sit in a pot and stir around with a with a spatula.

    CK: So, let's get into the metaphysical issue here the breath of a wok. Grace Young told me this. She wrote a book with that title. Her father, when they were younger, went to a restaurant Chinese restaurant, they'd sit right next to the door to the kitchen. He said that breath of wok lasts only a few seconds. (Right) when they came through with a food, he could smell it. And he thought that was just a wonderful experience. Could you just explain what the breath of a wok is?

    JKA: It's like the fajita platter at Chili's, right?

    CK: You go to Chili's? Wait a minute. Hold on

    JKA: You know, I spoke to a number of different chefs and cookbook authors and asked them what they thought of the breath of a wok this idea of wok hei and in virtually all of them gave different answers. Ranging from the very physical, you know, is the smoky flavor of food that's cooked at a very high temperature in a carbon steel wok, you know something very, very matter of fact, to something much more metaphysical, like it's the it's the sound of the sizzling that you get from the wok when you're sitting outdoors on like a hot night in Beijing and you have a nice cold beer in front of you. And it's much more about the overall experience and the aromas that are filling the street and the restaurant as opposed to one specific thing. So really, I think it's a matter of your experience with it. So, for me, you know what I learned as the breadth of a wok until Grace Young's book came out, I don't think many people called it the breath of the wok. And now that's just sort of the term that encompasses it. But for me, it was always when I went out to restaurants with my dad and my dad was obsessed with Chinese food. And so, we would spend weekends going around Chinatown, both in New York and Boston. Then the thing that he always particularly liked was when the chow fun had that nice smoky flavor. Like that was all that was always the refrain to hear my head like we would go to places like oh yeah, this is a great Chow fun. It has that nice smoky flavor. And that's what he called it right? Just that nice, smoky flavor. And it was something that I heavily associated just with restaurants. It wasn't something that even when we tried to make chocolate at home, it wasn't something that we ever really got at home was a part of it I think for a lot of people is that overall experiential thing of going to a restaurant and, and having someone cook for you and being surrounded by the sights and the smells.

    CK: So, let's do a how to cook and a wok one on one. And one of the things you start off with is if the dish includes me, you talk about washing the meat, vigorously washing the knee to water, squeezing it out as hard as you can, and then marinating it through massaging, slapping, lifting, and throwing. Yes, and I know you tested this because you test everything, but just take us through the washing of the meat please.

    JKA: Yeah, so if you're eating a steak in a Western restaurant, you expect the meat to have some kind of chewiness to it, right? You want you want some chew; you want some give in there. So, it's this balance of tenderness and toughness that you're looking for. Whereas a lot of times with stir fried meats, in Chinese restaurants, you want them to be very, very tender, and you want them to almost have like a, like a sort of slickness a slippery texture to them. And there's two important steps to getting there. The one that I'd known about for a long time was the marination process, and particularly using alkaline ingredients in the marinade. So brining meat with baking soda and salt, or in some cases, sodium carbonate, baking soda. Or, for example, in meats that are velveted, it, you would use egg whites and egg whites are also alkaline. The other process though, is one that I didn't really recognize as very important until I saw people doing it online, particularly the chef Wang Gang, Sichuan chef who has a YouTube channel. You know, I started seeing these videos of Chinese chefs actually washing the meat and the way they do it is extremely vigorous. It's like you're washing clothes, like you're scrubbing clothes, and really wringing it out. And so, I tried it at home. And it was like, I mean, the difference between meat that's vigorously washed in water versus meat that is not washing just marinated, it's enormous like it, it really completely changes the texture of the meat.

    CK: And why do you think that is?

    JKA: Well, I mean, I think it's, it comes down to just sort of mechanical tenderization. You know, and it's really interesting to me, because in a lot of Western cuisines, you know, like you think of like, French cuisine, right? And, and a lot of the goals in French cooking is concentrating the flavor. So, you might take like a chicken, right, you take the breasts off, you roast the carcass and make a stock out of that. And then you reduce that stock very slowly. And so, you're really concentrating all the flavor of the chicken, and then you'll serve that reduced juice with the roasted breast, right. Whereas with a lot of Asian cuisines, that's not really the goal. It's much more about balancing flavors. So, a dish of like beef and broccoli, right? We don't necessarily associate that with like a very strong beefy flavor, we really associated with more of the balance of meat and vegetables, the balance of sweetness and savoriness and aroma in the sauce. And so, when someone says, well, when you wash the meat, aren't you really washing out, like the beefy flavor? Well, in some way yes, you are. But then you just have to ask yourself again, it's sort of like resetting your expectations. Like that's a bad thing in French cuisine, but it's not necessarily a bad thing in some Chinese cuisines

    CK: Well, that's my speech, you just stole my speech. But we both been giving the same speech for years. So, we've prepped the ingredients, the meat, or the shrimp, just take us through a basic approach to add a stir fry in a wok.

    JKA: Okay, well, so I'll start this with the caveat that this is a very broad, you know, there are many, of course, many recipes that call for different techniques than what I'm about to walk you through. So, but but it's a very broad overview, the technique I would do at home, you know, so the first thing that I would recognize at home is that my home burner only has about 10 to 15,000 BTU, you probably, so about 10 times less than a restaurant or two. So, the main thing to remember is that you want to cook in batches. So typically, what I'll do is I'll start by cooking my meat, and I'll cook it no more than a third to half pound at a time. So, if that means you know, I'm cooking for four people, I might cook in two batches of meat, and each time, what I would do is I would rub a very thin film of oil into my carbon steel wok and then heat that and that thin film of oil is really just there as a temperature indicator. So, I'll know that when the walk starts sort of lightly smoking, that it's at the right temperature to start stir frying, what they do in restaurants. And what some home cooks call for, is they'll preheat the wok until it's really hot. They'll dump in a whole bunch of oil, and then they'll pour it out. Then they'll heat up that whole walk until they start smoking and then add some fresh oil and start cooking. In Western cooking, you would call for putting the oil in as your pre-heating because generally you don't get the oil hot enough that it really starts to break down right. Whereas in wok cooking, you're generally cooking at much higher temperature. So, if you try just pre heating all the oil that you're going to be stir frying in from the very beginning. By the time it's hot enough to stir fry in bite, like really smoking hot, the oil will have started to break down and developing some kind of off burnt oil flavors. So that's why I recommend just doing a really thin film as a temperature indicator than just before you start cooking. You add some fresh oil in there so that doesn't have a chance to break down. And so, once you do that, you would start by adding aromatics. Depending on the recipe, you could add aromatic straight to that oil so something like slices of garlic and ginger. Stir fry them very briefly just to get the flavor into the oil and then add your meat, stir fry it just until it's almost cooked through and then transfer it out onto a sheet tray. And then you repeat that with as many batches of meat as you need. And then after that, you would switch over to your vegetables. So, you do the same process. Preheat the wok, add some fresh oil, add your vegetables in there, stir fry them, and then set them aside on a sheet tray. And then at that point, if you want to add some of that smoky wok hei flavor. If you know if it's appropriate for the recipe, what you can do is you just take a kitchen torch, so I use like a butane torch, and then just pass it over the ingredients that you have laid out on the sheet tray so that the oil on their surface vaporizes and burns a little and cinges and adds that sort of smoky flavor. And then finally, right when you're ready to serve you preheat the wok again. You add all your ingredients back in at the same time you drizzle your sauce around the edges of the wok so that it really has a chance to reduce and cook really rapidly as opposed to sort of slowly trickling down through the food where it'll just steam. And then you toss everything together. Maybe 30 seconds maximum in there and then plate it up and you're ready to go.

    CK: You're listening to Milk Street Radio. My guest today is J Kenji Lopez Alt. After the break, we'll continue our conversation about his latest book The Wok, please stay with us. This is Milk Street Radio. I'm Christopher Kimball. Right now, we returned to my interview with J Kenji Lopez alt about stir fry techniques and his latest book, The Wok. Let's talk about woks. There are lots of different shapes. They're sort of flat bottom. They're the more conical original design. They're very light, very thin, carbon steel, they're heavier ones, what do you buy?

    JKA: So, my basic suggestion for anybody cooking on a western range, buy a 14-inch wide, flat bottom wok made out of carbon steel, that's 14 gauge, so about two millimeters thick. You know, that's what I've used for the last 20 something years and I think it's the most useful size and shape for a Western kitchen for someone cooking for you know, a small group or for a family, it will work on pretty much any western range. It's large enough that you can fit a bamboo steamer in there. It's large enough that you can deep fry or simmer or steam or you know anything in there. But yeah, that that would be my recommendation.

    CK: Are there some unusual things you do with the wok? I was in Thailand a few years ago and I would they would cook eggs and oil at the bottom of the wok? It's almost I wouldn't say deep frying them but they they were almost poached in oil I guess I would say yeah. Which which was really interesting. Are there other things you do in your book or otherwise that people wouldn't normally think of doing in a wok?

    JKA: I mean, so there is like a huge egg chapter in the book. And I would say the range of textures that you can get out of an egg cooking in a wok out number even the range of textures that you find in typical Western cooking, and you know and eggs you can get so many textures from silky to crispy to puffy to tender. And so yeah, you know, one of my favorite recipes in this book is called slippery beef. And this is really a homestyle dish. It's not something you'd really find at a restaurant but essentially you start by stir frying some aromatics and some strips of beef and then you add wine and stock and quite a bit of stock, you know a couple cups of it and then you thicken it up really heavily so that it's almost like the texture of like like a like gravy with a cornstarch slurry. So so and then after that you you beat your eggs and you very slowly drizzle them in the way you would do for say something like egg drop soup, but you know instead of having that texture of a soup with with silky strands of eggs the whole thing becomes this really sort of tenders silky I mean you know silky slippery thing that all these textures that that sound unappetizing in Western cuisine, but are extremely I think comforting and delicious when done in this context.

    CK: Toasting salt in a wok talk about that.

    JKA: Oh, yeah. So one of my favorite dishes we used to go to this restaurant in New York called Phoenix Garden and their signature dish were these salt and pepper shrimp and so they had these giant shell on prawns that they would deep fry and then toss with the salt and pepper mixture and it always had this really strong smoky flavor and you know I for a longtime assumed okay, they're deep frying it and then they're stir frying it afterwards to get that flavor but then as I researched the dish more, I found the flavor is actually not coming from stir frying the shrimp. It's coming from salt that they've essentially stir fried. And so, I thought to myself, like how on earth could just cooking salt in a wok give it a smoky flavor. So, I went on Twitter, and I asked people like, asked people to help me design some experiments. And I spent a night just basically testing things out and posting the results. But as I wrote in that New York Times story about wok hei, the three basic flavors that I associate with wok hei are the smokiness that comes from vaporized oil, the seared sauces that you get from adding sauces directly to hot metal and the flavor of that black oxide interacting with food. So, the smokiness that comes directly from the wok surface itself, and that's what the salt will capture. So, if you put salt in a wok, and heated up until it's basically smoking, the salt noticeably changes color, it becomes sort of darker gray, and then when you take it out and season food with it, it has a very distinct sort of wok hei aroma. And so yeah, what I do is I make I toast a bunch of salt. I take it out then I toast some central and peppercorns and white pepper in the wok, and then I grind it all together pound it all together in a mortar and pestle. And that's what I use as my sort of smoky salt and pepper blend. That is great on fried shrimp. But it's also great on you know, it's great on eggs, it's great on vegetables, whatever you want to have a little bit of smokiness to it's a good seasoning salt.

    CK: Every time I talk to you, you surprise me.

    JKA: Well, that’s good.

    CK: I always learned something I just would never have thought about like, toasting salt in a wok. Kenji it's been a pleasure, of course. Thanks so much for joining us here on Milk Street.

    JKA: Alright, thanks, Chris.

    CK: That was J Kenji Lopez Alt. His book is The Wok Recipes and Techniques. You know, I've known Kenji for at least a dozen years ago, we started working together. And he always brought a knack for engineering. For example, he turned a weber grill into a liquid smoke machine. And he also had a lot of curiosity. He found out that using vodka in pie dough, for example, makes them more tender crust because the alcohol evaporates during baking, resulting in less gluten development. His success is an appreciation that science is really just a tool, not an end in itself. You know, most of us don't care about, let's say Renaissance fresco techniques. We just enjoy looking at the Sistine Chapel. So, I would say the arts including cooking are reflection of our humanity, not our science. You know, good food is good food no matter how you get there. You're listening to Milk Street Radio. It's time to chat with J.M. Hirsch about this week's recipe. Moroccan flatbreads. JM how are you?

    J.M. Hirsch: I'm doing great.

    CK: Here's my question. When is the flat bread not a flat bread?

    JM: When you're in Fez, and you're eating Khobz
    CK: Yeah, this does not look like a flat bread, but it doesn't look like a typical European loaf either.

    JM: And no, no, it's you know, it's actually somewhere in between because it is yeasted so it's not truly flat. It's you know, kind of like a puffy, flying saucer shape, actually. But I'll tell you it's delicious.

    CK: Just to go back khobz is a bread that is eaten at every meal, sort of your all-purpose bread, utensil dipping bread of choice. It's used for everything.

    JM: Yeah, actually, you know, this is eaten at breakfast, lunch and dinner. It is used to sop up all the juices of everything. You know, silverware is not common in traditional Moroccan dining. This is your silverware. You use this bread to sop everything up and it is so delicious. It's got the perfect spongy texture to really absorb all the delicious juices.

    CK: A lot of flat breads do use yeast, but this is a lot thicker. So, what's the basic approach here?

    JM: So, you're basically just taking all-purpose flour and a little bit of semolina flour which gives it a nice granularity and nice texture to it and a little bit of wheat bran which does the same thing. And I learned our version of the recipe from a home cook Houda Mehdi and she likes to add a lot of seeds to her bread as well. And I thought this really put hers over the topic. She added sesame seeds, flax seeds, fennel seeds, and it just added both texture and taste. That was phenomenal. All she did was mix it together and let it rise very briefly, actually. But the special part of baking bread in Fez is the ferrane or the community oven. And this is where home cooks take their shaped and risen dough to literally the communal oven in their neighborhood where a baker will bake the bread for them for the equivalent, you know, a few pennies a loaf, they leave it it gets baked for them and then they go back and get it later and they have wonderfully baked bread.

    CK: So, this is probably the same thing that Crotchets did with their Christmas goose I mean the communal oven was also in London and lots of other places around the world, right?

    JM: Right, that's in the we see across cultures, it's an economy of fuel, one oven can feed an entire community. You know, one of the things that I heard over and over again, about these ovens in Fez is that they are losing ground because of the convenience of home electric ovens. But a lot of people still prefer to bring their bread to the ferrane, the communal oven, because of the taste, you know, these are wood fired old school ovens, and you really can't taste the difference.,

    CK: Well, also you can exchange gossip and see your neighbors and go on a walk right?

    JM: Exactly.

    CK: So, you shape it, is this bake just on a baking sheet or how do they actually bake it?

    JM: Well, you know, obviously, in the communal ovens, it's a stone bottom oven, and they throw these bread loaves on the peel, they throw them in the oven, they come out a few minutes later, we do it in a conventional oven. And they come out just as good though, we just do them on a baking sheet, and they cook up great. The fun part though, and you can do this at home if you choose to. But in Fez, it's essential is the baker or the home cook will put light indentations in the top of their loaves before they're baked. And this is a very important thing. It identifies the loaves. I mean, you know, when you're a baker cooking three 400 loaves a day for maybe you know, 100 different families, you're going to know whose bread is whose,

    CK: Well, I'll just write mine, on the top of all of them. So, it also the baker will bake bread for himself or herself. Yes, to sell as well. Right?

    JM: Yes, absolutely. And he has to be able to distinguish the loaves that are you know, to certain families and those that he is just going to sell, and you know, it also plays a role. It prevents it from rising too much, you know, deflates a little bit right before it goes into the oven. It actually does serve a real purpose as well.

    CK: So Moroccan flatbreads khobz, which really is a great, you know, three times a day bread, and it's easy to make it home. It's absolutely delicious. JM. Thank you.

    JM: Thank you. You can get this recipe from Moroccan flatbread at Milk Street

    CK: I'm Christopher Kimball, you're listening to Milk Street Radio. Right now, Cheryl Day and I will be taking a few more of your baking questions.

    CD: Thanks for calling Milk Street who's calling

    Caller: Bob Smith from Maslin, Ohio.

    CD: Hi, Bob. How can we help you today?

    Caller: Well, I made the Swedish cardamom bun from the November December 21 issue.

    CD: Oh, I love that recipe.

    Caller: Oh, and they were delicious. And not only that they were beautiful.

    CD: Well done.

    Caller: Unfortunately, my fiancé doesn't like cardamom. But she does like the texture of the bun. I was wondering, What can I substitute for the cardamom and what ratios could I use? And I'm hoping cinnamon is one of the answers.

    CD: Cinnamon is one of the answers. Cardamom is one of my favorite spices. But I'm glad she liked the texture and really the answer is what spices do you both enjoy?

    Caller: Well, almost all of them it's just cardamom is I think a little too floral for her.

    CD: Okay, okay, good to know. Cardamom, to me has a very complex flavor. It's very earthy warm, and I would definitely describe it as floral as well. I would try to do a combination of spices that kind of mimic that complexity, equal amounts of cinnamon and ginger would be a great choice. Basically, what you're trying to do is create a flavor profile that isn't just one note so I wouldn't do just cinnamon, but I definitely would do a combination of cinnamon and ginger in equal parts. I love coriander and a lot of people don't use this in baking, but I think that would be a great one to try. Ground coriander or Allspice, cinnamon and nutmeg would be a great flavor combination as well. And the ratio you know what just mix up if you want to just do, I don't want you to run out and buy a bunch of spices but if you have Allspice and cinnamon, you could do equal parts or if you have all spice cinnamon and nutmeg just do like a quarter teaspoon of each one would be great. Coriander I love I just love what it does to baked goods but I'm curious to know what Chris thinks

    CK; I have a prejudiced here I bought a month ago I posted this on social about don't put cinnamon in your apple pie. Oh, right. You're going to ruin it and I got I got 2 million views and hundreds of people mad at me about what do you mean no cinnamon. I think cinnamon tends to be overused and is overpowering. So, I do have a suggestion. If you get real cinnamon like Ceylon cinnamon, right, it is floral, but it's more savory. It's not quite as strong. You know, it's a much more interesting, complex flavor. You know, that might be a great thing to add here because it has the complexity that you'd find in cardamom. But it's more interesting than regular cinnamon. That's one thing you could try.

    CD: I just think mixing a couple because that cardamom in that recipe is so beautiful in that dough. You know, I think would be a shame to just do cinnamon. I think it'd be nice to do mix and play around with the flavors.

    CK: Yeah, and I think the coriander just like a half teaspoon of dander. I think that's the best suggestion that would really get you closer to cardamom.

    Caller: Okay,

    CK: That would be my choice.

    Caller: I'll try that.

    CK: All right.

    CD: Well, great.

    CK: Thanks for calling.

    CD: Thanks for calling.

    Caller: Thank you very much.

    CK: This is Milk Street Radio. If you have a baking mystery, give us a ring 855-426-9843 one more time 855- 426--9843 or email us at questions at Milk Street Welcome to Milk Street who's calling?

    Caller: Hi, this is Cathy.

    CK: And where are you calling from?

    Caller: Augusta, Georgia. I have a Pampered Chef ceramic Bundt pan that I have had for a long time and use successfully and recently like within the last year or so my cakes will stick to it. I have to use a rubber spatula to loosen the sides up and then when I turn it over, sometimes it doesn't come out at all. Sometimes part of it comes out and the rest of it doesn't. And I feel like I haven't done anything different. So, do I need to get rid of it? Get a new pan what's going on?

    CK: When it's dry? Is it feel smooth? Does it feel sticky? Is there residue on it?

    Caller: I think it feels smooth. I have been using like a spray oil.

    CK: Well, that’s There we go.

    Caller: That's the problem.

    CK: You can fix it. I mean

    CD: Just don't do it again.

    CK: The baking police are here. When you say ceramic it’s like a very smooth white porcelain style finish.

    Caller: It doesn't have a porcelain finish. It's

    CD: stoneware isn't that sort of?

    Caller: Yes, it is porous I think

    CK: I see. Okay, well, we found that soft butter with your fingers and get it right into the crevices etc. (CD: absolutely) a lot of it. It works. And we also like putting a little sugar on top of that. So, you get sort of a nice crunchy topping. But I don't know how you're going to fix a porous Bundt pan once it gets sticky. Would you know how to receive and Cheryl,

    CD: Specifically with that Pampered Chef recipe you're going to need to at least give it a try to re-season it. But you're going to want to kind of follow their instructions of doing a baking soda paste with a little water and cleaning it out first and then attempting to re-season it.

    Caller: Here's the other thing I thought about. I wonder if after I use it when I'm sitting it in the sink with some water in it. Is that contributing to it not having the… because for years that worked great.

    CK: You know, that's a good point. I think that could be a problem.

    Caller: Okay.

    CD: And we're going to tell you to get a Bundt pan

    Caller: A new one

    CK: I think the answer is spend 30 bucks and whatever and get one that's not too like other not too dark colored sort of in between like a gold colored one. We use those a lot.

    CD: And if you are emotionally attached to that pan, maybe you can use it for other things.

    CK: Yeah. The centerpiece put some lemons in it

    Caller: Or put a plant in it.

    CK: There you go. Yeah, that's perfect.

    Caller: So, are you recommending a metal pan?

    CK: Yeah, they're nonstick. There's a brand I don't know if it's called Gold Tone is that gold finish?

    CD: And Nordic Ware pans.

    CK: And maybe that yeah, so it works fine.

    CD: But again, butter and a little you can do a little dusting of flour and kind of tap that out just old school. I'm old school when it comes to that. Or I do love Chris's idea with the sugar also, but you won't use the nonstick for those pans either.

    CK: Thanks for calling and good luck with that.

    CD: Thank you for calling.

    Caller: Thank you so much.

    CD: You too. Bye bye.

    CK: That's it for this week's show. If you tuned in too late or just want to binge listen every single episode, you can download Milk Street Radio on Apple podcast Spotify, wherever you want your podcasts. To learn more about Milk Street go to 177 Milk There you can download each week's recipe watch the latest season of television show or you can learn about our magazine and latest cookbook Vegetables. You can also find us on Facebook at Christopher Kimball’s Milk Street on Instagram and Twitter at 177 Milk Street. We'll be back next week with more food stories and thanks as always for listening.

    Christopher Kimball's Milk Street Radio is produced by Milk Street in association with GBH, executive producer Melissa Baldino, senior audio editor Melissa Allison, producers Sarah Clapp and Jason Turetsky. Production Assistant, Amelia McGuire, and production help from Debby Paddock. Additional editing by Sidney Lewis, audio mixing by Jay Allison at Atlantic Public Media in Woods Hole, Massachusetts. Theme music by Toubab Krewe. Additional music by George Brandl Egloff Christopher Kimball's Milk Street Radio is distributed by PRX