How to Make It
Preheat broiler to high. Line a jelly-roll pan with aluminum foil; lightly coat with cooking spray.
Combine soy, mirin, sake, oil, brown sugar, ginger, and garlic in a saucepan over medium-high heat; bring to a simmer. Reduce heat; cook 5 minutes or until thickened. Place chicken in a bowl. Pour soy sauce mixture over top; toss. Add green onions; toss. Spread mixture in an even layer on prepared pan.
Broil chicken 4 to 5 minutes; turn chicken. Broil 4 to 5 minutes or until chicken is done. Transfer to a serving platter. Sprinkle evenly with sesame seeds, and serve with toothpicks or skewers.