Slow Cooking: For example, stewed beef is simmered over a low flame. Before cooking, the beef is first cut into square pieces and blanched in boiling water to remove scum and impurities. At this stage, the beef fibers are contracting. The heat should then be increased to medium, and auxiliary ingredients are added for a brief simmer before reducing the heat again to low. Through this slow simmering, the contracted fibers of the beef gradually relax. When the beef is almost done, seasonings are added and it is stewed until tender. This method produces stewed beef that is excellent in color, aroma, flavor, and shape. If cooked over a high flame, the beef will lose its shape and appear unattractive.
Medium Heat Cooking: Suitable for deep-fried dishes. For ingredients that are battered, it is generally better to use a high flame to submerge them in the oil and then switch to a medium flame for frying, gradually adding more oil. This is because if the oil is too hot, the ingredient will burn on the outside while remaining raw on the inside. If the heat is too low, the batter will separate from the ingredient after it is placed in the pot. For example, Crispy Fried Chicken is prepared by first submerging the ingredient in the oil over a high flame to form a hard outer shell, then moving it to a medium flame to fry until crispy.
High Heat Cooking: Suitable for dishes that are stir-fried, quick-fried, or blanched. Dishes cooked over a high flame generally feature main ingredients that are crispy or tender, such as Scallion Lamb, Hot Pot Lamb, or Boiled Tripe. When boiling tripe, it must be placed in and removed from boiling water quickly to ensure it remains crispy and tender. If the heat is insufficient and the water is not boiling, the main ingredient will not contract in time and will become overcooked. Similarly, for Scallion Lamb, the meat must be sliced thinly. The wok must be over a high flame with the oil very hot. Add the oil to the wok over high heat until it smokes, then add the meat and stir-fry until it changes color. Immediately add the scallions and seasonings and stir-fry briefly until the scallions change color, then remove from the wok immediately. The key is to cook quickly over a high flame; otherwise, the dish will become watery or tough.