Practice:

1. Take a piece of pork belly with skin, put it in a pot with cold water, add onion ginger, cooking wine, prickly ash granules and star anise, and skim the bleeding foam.

2. Cut the pork belly into pieces, but don't cut it. Add one spoonful of allspice powder, one spoonful of Chili powder, one spoonful of cumin powder, one spoonful of salt and sugar, one spoonful of soy sauce and one spoonful of oyster sauce, and marinate evenly for 25 minutes.

3. Wrap the pork belly in tin foil, with the epidermis facing upwards, coat it with a thick layer of salt, and fry it in air at 200 degrees for 30 minutes.

4. Cut off the tin foil on the surface, remove the salt on the surface and coat it with a layer of white vinegar. White vinegar is the key to crisp surface.