2. Put the oxtail in cold water, boil it, remove the blood foam and remove it for later use;
3. Soak Flammulina velutipes in warm water, remove pedicels and wash for later use;
4. Fill the pressure cooker with water, pour in oxtail, add pepper, aniseed, cooking wine, onion and ginger slices, steam for 25 minutes, and cool to take out oxtail;
5. Heat oil in a wok, add oxtail and Flammulina velutipes, stir fry, add soy sauce to the soup cooked by oxtail, stew for 20 minutes, add salt, and collect juice over high fire.