Mix the meat with the garlic, ginger, scallions, water chestnuts, soy sauce, sesame oil, cabbage, and 1 tablespoon chili sauce in a bowl. Chill for one hour.

Place a wrapper on a metal dumpling press (of the same diameter). Put a small scoop of filling in the center, moisten the edges with a wet finger, and press. Repeat, using all the filling, which should make about three dozen potstickers. Refrigerate or freeze until cooking time.

Heat the oil in a pan over medium-high heat and cook the potstickers, in batches, on one side until bottoms are golden brown. add 1/2 cup of water, cover the pan, and steam for five minutes. Uncover and continue cooking until the water has evaporated. Serve with Chinese mustard and/or a sauce made with the black vinegar, soy sauce, and the remaining tablespoon of chili sauce.