The method of filling pork dumplings is as follows:

1. Pour onion, ginger, star anise (optional) and Sichuan peppercorns into a bowl, brew in boiling water, let cool, remove and set aside. Add onion, ginger, and pepper water and set aside.

2. Use a meat grinder to mince the meat, (or buy the minced meat directly from the supermarket packaging box) and chop the celery and mushrooms. Crack an egg into the meat filling, add three spoons of cooking wine and stir evenly. Add some salt to the celery to control the moisture.

3. Add two spoons of light soy sauce, one spoon of dark soy sauce, two spoons of oyster sauce, one spoon of chicken essence, one spoon of salt, thirteen spices and a little pepper to the meat filling. Add minced meat and stir.

4. Add the minced onion and ginger and stir evenly. The more onions, the more fragrant the meat filling will be. Pour in the onion and ginger water three times. After each pour, stir the meat filling clockwise vigorously, and then pour in the next time. Add onion, ginger and water until the meat filling no longer absorbs water.

5. Mix the celery and shiitake mushrooms with the meat filling respectively and stir evenly. The dumpling filling is ready.