To Prep
Lightly season the cooked rice with table salt.
Using a generous piece of plastic wrap, place portion of cooked rice, add filling in the center (optional), wrap with plastic wrap, then mould into balls.
To Cook
Lightly spray the grill of the broiler grill with cooking spray to prevent the rice ball from sticking.
Over medium heat, allow the rice ball to grill on both sides until golden brown and slightly crisp. Time may vary from 15 to 20 mins depending on your grill.
Drizzle soy sauce over yaki onigiri and serve immediately.