Prepare Marinade: In a medium bowl, mix together soy sauce, minced garlic, grated ginger, and cornstarch until smooth. Add in the boneless chicken thighs, ensuring they are well-coated in the marinade. Cover the bowl and let the chicken marinate in the refrigerator for at least 30 minutes.

Heat Oil: In a large pan or wok, heat 2 tablespoons of vegetable oil over medium-high heat until shimmering.

Cook Chicken: Add the marinated chicken thighs to the hot pan and cook for about 5-7 minutes until golden brown and cooked through, flipping halfway.

Add Zucchini: Once the chicken is cooked, add sliced zucchini to the pan. Stir-fry for an additional 3-4 minutes.

Finish Cooking: Combine all ingredients in the pan gently and cook for another minute or two, until heated through and glossy.