In a large skillet, fry chicken, garlic and sauce in 2 teaspoons oil. Cook and stir until chicken is lightly browned and juices run clear; remove and keep warm.
In the same pan, stir fry vegetables in remaining oil for 4-5 minutes, or until heated through.
Add chicken and mix well.
Combine corn starch and cold water until smooth; stir into chicken mixture. Bring to a boil, cook and stir for 1 minute, or until thickened.
Serve over rice.