Onions can be used as an auxiliary ingredient or a seasoning in cooking. For ingredients with a strong fishy or gamey flavor, such as the offal of aquatic poultry and livestock, and eggs, adding scallions during cooking not only helps to mitigate the cold nature of shellfish but also has anti-allergic effects.
Firstly, the shape of the processed scallion should be consistent with the main ingredient. Generally, the scallion should be cut slightly smaller than the main ingredient, but this can be adjusted based on the cooking method. For example, "Braised Fish" requires scallions to be cut into sections and braised with the fish; "Dry-Braised Fish" requires scallions to be minced to match other ingredients; for "Steamed Fish," a whole scallion is placed on top of the fish and removed after cooking to impart its aroma without affecting the fish's appearance; for "Fish Ball Soup," scallions are soaked in water to extract the juice, ensuring the soup's clarity; for "Fish Soup," scallions are fried in sections before being stewed with the fish to enhance the aroma and remove the fishy smell; after cooking, the scallion sections are removed, leaving the soup clear and not cloudy. Scallion puree or juice is mainly used in dressings for cold dishes to achieve a light, fragrant scallion oil flavor.
Secondly, the cooking method directly affects how scallions are prepared in a dish. For dishes cooked quickly over high heat, where a thickener is often added directly to the wok, scallions are typically used in one-inch sections, such as in "Scallion and Egg Stir-fry" or "Scallion-Covered Sea Cucumber." Additionally, when making baked fish, whole scallions are used to line the bottom of the pot instead of smaller pieces like sections or minced scallions. This prevents the scallion aroma from dissipating too early and avoids the issue of the ingredients sticking to the pot. Finally, it is advisable not to add scallions when making soups, as their strong flavor can overpower the natural taste of the broth.