1. Cut the trotters into pieces and put them in a pot with water, add pepper, star anise, green onions, ginger, and simmer for 15 minutes on medium heat
2. Put oil, rock sugar, ginger slices in another pot, pour in the processed trotters
3. Add cooking wine, dark soy sauce, and pour in cold water until the trotters are covered
4. Simmer for 1 hour
5. Add salt, just out of the pot
