1. waterless stewing: waterless stewing is to put the raw materials into boiling water to remove blood stains and fishy smell, then put them into a pottery vessel, add seasonings (seasoning food) such as onion, ginger, wine and water (generally, the amount of water can be slightly more than that of raw materials, such as 1.5 kg to 2 kg of water for 1 kg of raw materials), cover them and cook them directly on the fire. When cooking, first boil with high fire, skim off the foam, and then simmer with low fire until crisp and rotten. The stewing time can depend on the nature of the raw materials, usually about two or three hours.

2. Waterproof stewing method: Waterproof stewing method is to put the raw materials into boiling water to remove the fishy smell, then put them into porcelain and pottery bowls, add onions, ginger, wine, soup and other condiments, seal them with paper, put the bowls into a pot of water (the water in the pot should be lower than the spout to avoid artificial soaking in boiling water), and cover the lid tightly to prevent air leakage. Burn with fire. Leave the pot on forever, and it will stew in about three hours. This stewing method can make the fresh flavor of raw materials difficult to lose, and the cooked dishes are rich in flavor and clear in soup color. Some put a sealed bowl of raw materials on a boiling steamer, and the effect is basically the same as that of stewing without water. However, due to the high temperature of stewing, the steaming time must be mastered.

Nutritional value of fish

Fish protein is a kind of high-quality protein, with the content of 15 ~ 20% and the utilization rate as high as 85 ~ 90%. The amino acid composition is balanced, but the tryptophan content is low. Fish contains more water and tender meat, which is more easily digested and absorbed by human body than livestock meat. The fat content of fish is about 1 ~ 10%, which mainly exists under the skin and around organs.

The fat content of different fish species varies greatly, such as the fat content of big fish is 0.5%, whitebait is 5.6%, and the fat content of river eel is as high as 10.8%. Fish fat is mostly liquid, with low melting point and high polyunsaturated fatty acid content, which is better than animal food such as livestock, poultry, milk and eggs with high saturated fatty acid content.