Mix ground chicken, garlic, ginger, leek, coriander leaves, oyster sauce, sesame oil, Sasa Gourmet Powder, white egg, salt, and pepper. Stir well.
Take one gyoza sheet, fill with a tablespoon of the chicken mixture. Fold into two pieces, then stick them together with white egg, then make some pleats on its edge.
Steam for 10 minutes, set it aside. Heat some margarine on a pan, then add the gyoza and cook until it changes color. Serve with condiments such as soy sauce and roasted sesame to taste.