There are three main things you want to avoid when eating or ordering takeout on keto. The first are foods cooked in vegetable oil. The second thing to look out for is sweet sauces; the third is hidden carbs. Beef cooked in a Chinese restaurant may often be water-velveted, a technique for marinating meat in cornstarch before cooking. These hidden carbs can mess with your macros. Therefore, you're better off making homemade keto-friendly stir fry recipes instead.