Step 1: soak the ribs in clear water for a while, rinse them several times to remove blood, and wash the yam.
Step 2: Peel and cut the yam.
Step 3: Stir-fry the ribs and rinse them.
Step 4: Heat oil in the pot, add onion and ginger and saute until fragrant.
Step 5: Stir-fry the ribs, add the soy sauce and soy sauce and continue to stir-fry for a while.
Step 6: Pour enough hot water, bring to a boil with high fire, add star anise and cinnamon, and stew for 30 minutes on medium fire.
Step 7: Add the yam and continue to stew for 20 minutes until the yam becomes soft and the soup becomes thick.