In a small bowl, whisk together the soy sauce, honey, rice vinegar, minced garlic, and grated ginger. In a separate tiny bowl, mix the cornstarch and cold water to create a slurry. Set both aside.

Heat the avocado oil in a large skillet or wok over medium-high heat. Add the chicken pieces in a single layer and cook for 5-7 minutes, stirring occasionally, until golden brown and cooked through. Remove the chicken from the skillet and set it aside.

Add the broccoli florets, sliced bell pepper, and carrots to the same skillet. Stir-fry for 4-5 minutes until they are tender-crisp.

Return the cooked chicken to the skillet with the vegetables. Pour the teriyaki sauce mixture over everything and bring it to a simmer. Stir in the cornstarch slurry and continue to cook for 1-2 minutes, stirring constantly, until the sauce has thickened and coats the chicken and vegetables.

Garnish with sliced green onions and a sprinkle of sesame seeds. Serve immediately over rice or noodles.