Combine all ingredients other than oil in a bowl and mix well by hands. Place a teaspoonful of filling in a gyoza wrapper and put water along the edge of the wrapper by fingers. Make a semicircle, gathering the front side of the wrapper and sealing the top. Heat oil in a frying pan. Put gyoza in the pan and fry on high heat until the bottoms become brown. Turn down the heat to low. Add 1/4 cup water in the pan. Gyoza is a kind of dumplings originated in China. Gyoza can be steamed, fried, boiled, and more. This is a recipe to make the most poular pan-fried gyoza. Cover the pan and steam the gyoza on low heat until the water is gone.