In 2-quart saucepan, heat oil over medium heat. Cook chicken in oil 4 to 6 minutes, turning once, until browned. Remove chicken to plate; cover to keep warm.
In same skillet, cook onion over medium heat 3 to 4 minutes, stirring occasionally, until softened. Stir in cinnamon and cooking sauce. Return chicken to skillet, gently pushing down into sauce. Cover; cook 10 minutes or until juice of chicken is clear when center of thickest part is cut (at least 165°F).
To serve, divide chicken, onion and sauce among 4 plates. Sprinkle with orange peel.