Preheat 3 TBS of the oil over medium- high heat 3 to 5 minutes or until hot. While the oil is preheating in a small bowl whisk together all other ingredients except the chicken and vegetables until smooth. Set aside. Place the chicken in the preheated skillet. Stir to coat with the oil. Add salt and pepper to taste.
Cook the chicken over medium-high heat for 5 to 7 minutes or until the chicken is heated through. Stir and turn the chicken occasionally while it is cooking. Add the vegetables and stir to combine. Pour the sauce over the vegetables and stir to fully coat the chicken and vegetables with the sauce.
Bring the mixture to a low boil. Cook 7 to 10 minutes or until the sauce has thickened. Spoon desired amount onto serving plate. If desired serve the sweet and sour chicken over some cooked keto rice or keto pasta of choice.