The best beef for a stir fry has a good mix of lean meat and fat and remains tender even if cooked quickly. While I use patio steak for this stir fry, you could use other cuts of steak. Try to avoid getting one that has a high fat content, like porterhouse steak. I also wouldn’t use roast cuts, such as chuck roast or round roast, or something like skirt steak, which can be tough if not cooked correctly.