In the Thai kitchen, kratiem prik Thai is an aromatic, flavor-packed paste of garlic, black pepper and cilantro root. It often is used to season meat and seafood, but in this recipe we combine the ingredients (we substitute cilantro stems for hard-to-find roots) to add punch to a simple vegetable stir-fry. Napa cabbage and mushrooms provide meaty flavor, while snow peas (or bell peppers) offer color, sweetness and crunch. If you don’t have fish sauce or want to make the dish vegetarian, use an equal amount of low-sodium soy sauce.