Chao Stir Fry Technique
The chao technique is similar to the Western technique of sautéing. There are regional variations in the amount and type of oil, the ratio of oil to other liquids, the combinations of ingredients, the use of hot peppers, and such, but the same basic procedure is followed in all parts of the country.
After heating the wok to a high temperature, and just as or before it smokes, a small amount of cooking oil is added down the side, followed by dry seasonings such as ginger, garlic, scallions, or shallots. The seasonings are tossed with a spatula until they are fragrant, then other ingredients are added, beginning with the ones taking the longest to cook, such as meat or tofu. When the meat and vegetables are nearly cooked, combinations of soy sauce, vinegar, wine, salt, or sugar may be added, along with thickeners such as cornstarch, water chestnut flour, or arrowroot.