1. Cook rice according to package directions. Transfer to bowl. Place chicken, edamame, and onions in food processor, and pulse until finely minced.
2. Heat skillet to medium high, add oil. Sauté chicken-edamame mixture 5–8 minutes, until onions are soft. Stir chicken mixture into rice.
3. Wet your hands with water, and form mixture into 12 tightly packed triangle-shaped rice cakes. Roll half in rice seasoning, and place in a flat container. (Alternately, pack rice with a small round ice cream scoop, place in flat container, and sprinkle tops with the rice seasoning.) Refrigerate until ready to eat or pack. Serve with soy sauce for dipping.