Slice the boneless, skinless chicken into thin strips. Wash and slice the zucchinis into half-moons, and slice the red bell pepper into strips if using. Mince the garlic cloves.

Whisk together the soy sauce, oyster sauce (if using), honey, and sesame oil in a small bowl until well combined.

Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat. Add the sliced chicken, season with salt and pepper, and cook for about 5–6 minutes until golden brown.

Transfer the chicken to a plate and set aside. In the same skillet, add the remaining tablespoon of vegetable oil and sauté the sliced zucchini and bell pepper for about 3–4 minutes until tender but still crisp.

Add the minced garlic and cook for an additional 30 seconds until fragrant; return the cooked chicken to the pan and pour the prepared sauce over everything. Toss to mix well for 1–2 minutes.

Remove from heat and transfer the Chicken Zucchini Stir Fry onto a serving platter. Garnish with sesame seeds and green onions.