The secrets of cooking Dongpo pork knuckle are as follows:

1. Choosing pork knuckle: Choose pork knuckle with skin and a certain amount of fat. Too much lean meat will result in less delicious taste.

2. Ingredients preparation: Wash the pork knuckles and blanch them in boiling water to remove blood and impurities. Then soak in warm water for 2 hours to remove excess salt and odor.

3. Pickled elbows: When pickling, you need to add cooking wine, ginger slices and green onions, and marinate for 2 hours. It can make the elbow more delicious.

4. Cooking the elbow: Put the marinated elbow into the pot with the onions and ginger, add an appropriate amount of water, bring to a boil and add rock sugar, cooking wine and soy sauce to taste.

5. Cook the elbow: Reduce the heat and simmer for 1-2 hours to make the meat of the elbow soft and delicious, and to make the soup richer.

6. Add vinegar and chopped green onion: After turning off the heat, add an appropriate amount of vinegar to increase the sourness and texture, and garnish with chopped green onion.

Through the above steps, you can make Dongpo elbow with delicious texture and soft meat.