Preheat oven to 425º F. In a small saucepan over low heat, mix the cornstarch, water, sugar (or Truvia), soy sauce, vinegar, garlic, ginger and pepper. Let simmer for a few minutes, stirring until thickened.
Spray the bottom of a 9x13 pan with cooking spray. Place chicken breasts in the bottom of pan and pour teriyaki sauce over chicken. Cover pan with foil.
Bake covered for 25 minutes and then take the foil off and continue cooking for about 15 minutes, or until chicken is cooked through and no longer pink inside (165 degrees).
Meanwhile, have your rice steaming in a rice cooker and cook your stir fry vegetables. Take chicken out and let cool while you prepare the bowls: add rice to the bottom of the bowls, then a layer of vegetables. Slice up your chicken and layer on top. Drizzle with remaining teriyaki sauce and sprinkle with sesame seeds. Enjoy!