In a small bowl, whisk together teriyaki sauce, soy sauce, and vinegar. Dissolve cornstarch in 1 tbs. water and stir into the sauce mixture. Set aside.

In a large skillet over high heat, heat oil and stir-fry chicken 2 minutes.

Add veggies and cook about 2 more minutes until chicken loses its pink color and veggies soften

Add sauce to skillet and cook, stirring, until heated through and sauce is thickened.

serve over white rice