Made the Italian way, fettuccine Alfredo bears little resemblance to the unctuous, cream-based pasta dish that’s popular in the U.S. We scoured Rome for the best versions, and our favorite was prepared by home cook Francesca Guccione who resides in Castelnuovo di Porto, just outside of the city. Rich, luxurious and elegant but neither heavy nor cloying, Guccione’s fettuccine Alfredo, like other Roman recipes for the dish, consisted of only fresh pasta, Parmigiano Reggiano cheese, butter and salt. The secret lay in using high-quality ingredients and combining them in just the right way, and in just the right volumes. We adapted her winning formula but incorporated a technique we saw employed at a couple restaurants of putting softened butter (rather than melted) into the bowl in which the hot pasta will be tossed. Of utmost importance is the cheese. Purchase a hefty chunk of true Parmigiano Reggiano—not the pre-shredded stuff—trim off the rind (save it for simmering into soups and stews), cut 6 ounces into rough ½-inch pieces and whir them in a food processor until very finely ground. This helps ensure the cheese melts readily. High-fat butter also is key. In Europe, butter typically has a fat content of around 85 percent; standard American butter is only about 80 fat. That 5 percent difference has a big impact on the flavor and consistency of the finished dish. At the grocery store, some types of high-fat butter are labeled “European-style”; Plugrá and Kerrygold are two widely available brands. If the butter also happens to be cultured, all the better, but this is not essential. We learned from Guccione that patience also is an important ingredient. Tossing the pasta with the cheese in small additions and while gradually adding some starchy pasta-cooking water takes time but yields a sauce that is velvety-smooth. We highly recommend serving the pasta in individual bowls that have been gently warmed.