1. The big bone is soaked in water for one day.

2. Remove the blood, such bones, the cooked soup will be white, and there is no fishy smell.

3. Add ginger slices and onion knots to the washed bones again, boil them in a pressure cooker and simmer for an hour. This is the key to thick and white soup. If you don't have a pressure cooker, you have to use the stove for two or three hours. Cook until the bones are rotten.

4. The cooked soup is thick and white