Bring a pot of salted water to a boil. Blanch the shredded cabbage until it is tender but still crisp. Plunge into ice cold water, remove, and drain thoroughly.
In a large bowl, combine ground beef, cabbage, onions, ginger, hot chilli oil, soy sauce, sesame oil, pepper, salt and egg. Mix well to ensure everything is well combined.
Lay a gyoza wrapper in front of you. Wet all the edges with water. Place 1/2-1 tablespoon of filling in the middle of the wrapper.
Fold the sides up to form a semicircle, and then pinch the edges to seal. Continue with the rest of the gyoza wrappers until the filling is gone.
To cook, heat 1 tablespoon oil in a heavy frying pan over medium-high to high heat. Add about 8 gyozas and cook for 2 minutes, or until golden brown on the bottom.
Add 1/2 cup of water to the pan. Cover the dumplings and steam until the water is absorbed (5 to 7 minutes).
Repeat with the remainder of the gyoza dumplings.
Serve with Vinegar and chilli powder or chinese style, soy sauce and red cut chillies.