Blanch beef, stew in boiling water for 20 minutes, add potatoes and onions, stir fry, pour beef and beef soup cooked in another pot, add butter, add tomatoes and a little tomato sauce, and stew for 20 minutes. Add Chinese cabbage, cook for 10 minute until the cabbage is soft, add salt, add one spoonful of white vinegar or rice vinegar, add two spoonfuls of milk, and stew for 10 minute.