Place 1/2 cup rice in a bowl; cover with water to 1 inch above rice, and let stand 1 hour. Drain rice well; place rice in a shallow dish, and set aside.
Combine chicken and next 7 ingredients (chicken through oil) in a large bowl; stir well. Drop chicken mixture by rounded tablespoons into rice, rolling to form rice-coated balls.
Line a bamboo steamer with steamed cabbage leaves. Place balls 1/2 inch apart in steamer; cover with steamer lid. Add water to a large skillet to a depth of 1 inch; bring to a boil. Place steamer in skillet, and steam balls 20 minutes or until rice is tender. Remove balls from steamer.