2. Put a little oil in a hot pan. When the oil is hot, pour in the duck pieces. Stir-fry until the duck shrinks and changes color. Pour in a little cooking wine, then add chopped green onion, ginger slices, star anise and cinnamon and stir well.
3. Add soy sauce and soy sauce, stir-fry and color evenly.
4. Add clear water, enough at a time, the clear water should not pass the duck meat, and after the fire is boiled, turn to medium and small fire for 10 minutes.
5. Add potatoes and salt, add a few drops of vinegar (which can remove the fishy smell), and continue to keep medium heat. In order to keep the potatoes intact, please don't turn them all the time.
6. Turn off the fire when the soup is thick and dry. Finally, stir-fry the chopped green onion and serve.