Slice an onion and a green onion into small pieces.
In the middle bowl, combine ground pork and the onions. Add other seasonings, sugar, cesami oil, sugar, soy sauce, sake,ground gingers and potato starch.
To wrap the siu mai, place two tablespoons of filling on a middle of a siu mai wrapper.
Wrap the filling with the siu mai wrapper.
To steam, put a small dish on the bottom of a big soup pan. Place a small lid with holes (otoshibuta) on it. Pour water under the otoshibuta. Heat the pan to boil water.
Place a wrapped siu mai on the otoshibuta. Place 10 siu mai dumplings at one time.
Put the lid on the pan. Steam them for 10 minutes.
