Begin by slicing the chicken breast into thin strips, ensuring even cooking. Dice the zucchini into half-moons and chop the red bell pepper into bite-sized pieces if using. Mince the garlic. In a medium bowl, whisk together soy sauce, oyster sauce, honey, and sesame oil; set aside.

Heat vegetable oil in a large skillet over medium-high heat. Once shimmering, add the sliced chicken and season lightly with salt and pepper. Sauté for about 5–6 minutes until golden brown and fully cooked. Remove from the pan and keep warm.

In the same pan, add more vegetable oil if needed. Add the zucchini and bell pepper, sautéing for 3–4 minutes until they start to soften. Add the minced garlic and stir quickly for 30 seconds.

Return the chicken to the skillet with the veggies, pour the sauce over, and toss everything together. Cook for an additional 1–2 minutes until the sauce coats everything and heats through.

Remove from heat and garnish with sesame seeds and green onions. Serve hot over rice, noodles, or enjoy as-is.