This is very simple. Carassius auratus should be washed after slaughter (gills should be removed, all internal organs should be removed, black things in the stomach should be removed, blood near the middle bone should be removed, and the scales should be scraped clean, especially the hard scales near the head should be cut clean with scissors). Then drain the water (wash it thoroughly with water, and dry it with a cloth when cooking dried fish), heat the pan, put oil in it, fry the fish on both sides until slightly yellow, add enough cold water once, boil it, add rice wine and ginger slices to remove the fishy smell, keep the fire for 10 minute, then change the medium heat until the fish soup turns white, and then add tofu to boil it. Add pepper, salt, a little monosodium glutamate and sugar, sprinkle some chopped green onion, and you're done.