Tooth-picking wing is a common shark fin, and its foaming rate is 300%. Put the tooth-picking wings into the pot, soak them in clear water for 24 hours and take them out. Fill a pot with clear water, bring it to a boil, add the soaked pedicle wings, and cook for 4 hours with low fire. Rinse the cooled wing stalks with clean water.

Add water to the pot, add onion and ginger, then add stems and wings, and cook for 5 hours. Rinse the cooled pedicle wings with clear water again. Put it in a steamer until it can be broken with chopsticks, then put it in a pot and boil it for an hour.