Mix chicken with 1 tablespoon light soy sauce, 1 tablespoon Shaoxing wine, and 1 tablespoon cornstarch in a bowl. Marinate for 10-15 minutes.
In a separate bowl, whisk together chicken broth, 2 tablespoons light soy sauce, 2 tablespoons Shaoxing wine, 2 teaspoons dark soy sauce, 1 tablespoon cornstarch, and 1 ½ tablespoons sugar.
Heat a skillet or wok over medium-high heat, add 1 tablespoon oil and spread the marinated chicken in a single layer. Sear for 1-2 minutes without stirring.
Stir-fry the chicken until cooked through and lightly browned, about 3-4 minutes. Remove to a plate.
Add remaining oil to skillet if needed. Pour in the prepared sauce and stir until thickened, about 1-2 minutes.
Return the cooked chicken to the pan and toss to coat with sauce.
Add ground black pepper and cook together for 1-2 more minutes.
Serve hot over rice or with vegetables.
Notes
Freeze leftovers in meal-size portions for quick dinners. Reheat with a splash of water or broth to restore the sauce.