2. Boil the cold water in the pig's trotters, so that the blood in the pig's trotters is exhausted, so that the treated pig's trotters are fresh and not fishy.
3. Put the blanched trotters into a casserole, and add ginger slices and garlic.
4. Pour in soy sauce, oyster sauce and pepper, and add star anise leaves and red pepper.
5. Mix salt with water and soy sauce into a sauce and pour it into the pot. Shake the casserole a few times to make the bottom full of sauce, so as to avoid pasting the bottom.
6. Cover the lid and cook over medium heat. After boiling, open the lid and turn the trotters over the bottom with chopsticks. Cover directly with 2 layers of pot cover, and simmer for 40 minutes on low heat.