1. Put the cleaned trotters into a casserole
2. Add ginger and oyster sauce
3. Bring a moderate amount of water to a boil on a high fire and a low fire
4. After boiled for 35 minutes, go down to the yam
5. Put in a handful of wolfberries before the yam is soft and rotten
6. Finally, add a little salt to taste
Tips:There is a lot of foam in the trotter boiled, the soup is less oily after removal, and the soup color is good
