This fast, easy, and healthy way to cook involves just two commitments to ensure that your food has wok hay, the hard-to-describe but delicious seared, slightly smoky taste that you've enjoyed in any good Chinese restaurant. First: a wok that's cast iron, stainless steel, or rolled carbon steel. Second: a willingness to get that pan really hot. With those two things in place, you can swirl the ingredients briefly, which preserves crunch and heightens natural flavors as the wok hay develops. These three steps are key for stir-fry success.