Sauté: Bring a wok or large cast iron skillet to medium-high heat. Add 1 tablespoon extra virgin olive oil and swirl to coat the pan. Add 2 cloves minced garlic and move around pan until it becomes fragrant, approx. 30 seconds.
Cook Chicken: Add cut-up chicken. As chicken cooks, add a tablespoon of teriyaki sauce, if it gets too dry and chicken starts to stick. Remove chicken once fully cooked, place on plate and set aside. Drain any remaining liquid.
Cook Veggies: Add remaining garlic and 1 tablespoon extra virgin olive oil. Stir and cook on medium heat until garlic becomes fragrant. Add broccoli and carrots. Cover and let cook for 3 minutes. Uncover, add 8 ounces water chestnuts and red pepper. Stir and cover for an additional 2 minutes. Uncover, add 8 ounces mushrooms, onion and return the cooked chicken to the pan. Stir and cover for an additional 2-3 minutes.
Add Sauce: Add approximately ½ cup teriyaki sauce and stir thoroughly. Add any additional teriyaki sauce to reach desired amount.