Place chicken in a mixing bowl and toss with the cornstarch until all is coated. Set aside.
Mix all sauce ingredients together and set aside.
Heat oil in a non-stick skillet over medium-high heat. Add the coated chicken and let it cook for 2-3 minutes until browned. Flip and cook another 2-3 minutes until browned. Remove chicken onto plate.
Add the broccoli and bell pepper to the skillet and stir fry for 2 minutes. Add the chicken back and pour on the sauce. Toss and cook for 1-2 minutes until sauce thickens. Remove from heat, sprinkle with green onions and green onion, and serve over rice.
