Prepare the chicken by cutting boneless chicken thighs into bite-sized pieces and marinating them in a mix of light soy sauce, sesame oil, cornstarch, sugar or honey, and optional rice wine vinegar for at least 30 minutes.

Sauté smashed garlic in a large wok or skillet over medium-high heat with cooking oil until fragrant, about 30 seconds.

Add the marinated chicken to the wok and cook until browned and cooked through, about 5-7 minutes, then set aside.

In the same wok, stir-fry the sliced zucchini for 3-5 minutes until bright green and tender yet crunchy.

Combine the chicken back into the wok with zucchini, drizzle oyster sauce, and season with ground black pepper if desired. Toss together over medium heat for 2-3 minutes.