In a mixing bowl, combine your chicken breasts (or thighs) with light soy sauce, Shaoxing wine, and cornstarch. Let it marinate for about 10–15 minutes.

While the chicken marinates, mix the sauce ingredients: dark soy sauce, sugar, chicken broth, and black pepper. Stir until the sugar dissolves and set aside.

Heat a skillet over medium-high heat and add peanut oil. Add the marinated chicken in a single layer, searing it for about 1 minute. Flip and continue cooking until no longer pink. Transfer to a plate.

Add more peanut oil to the skillet, then sauté minced ginger and garlic for about 30 seconds. Toss in the sliced onion and bell peppers, stir-frying for about 20 seconds.

Pour the prepared sauce mixture into the skillet with the sautéed vegetables. Stir and cook for a couple of minutes until thickened.

Return the cooked chicken to the skillet, mixing everything thoroughly. Heat together for another minute and serve immediately.