Preparation

Step 1: Marinate the Chicken

1. Begin by mixing soy sauce, oyster sauce, cornstarch, and black pepper in a bowl.
2. Add the chicken pieces to the marinade, ensuring they are fully coated.
3. Allow the chicken to marinate for at least 20 minutes. For deeper flavor, let it rest for 30 minutes to an hour.

Step 2: Prepare the Sauce

1. In a separate small bowl, combine soy sauce, oyster sauce, dark soy sauce, sugar, black pepper, and chicken broth.
2. Stir until the sugar dissolves completely and set the mixture aside for later use. Having the sauce ready ahead ensures smooth cooking.

3: Cook the Chicken

1. Heat oil in a large skillet or wok over medium-high heat.
2. Place the marinated chicken pieces in the pan in a single layer and sear for 2-3 minutes on each side. This will lock in the juices and create a golden crust.
3. Once cooked, remove the chicken from the pan and set it aside on a plate.

4: Stir-fry the Vegetables

1. Add a little more oil to the same pan if needed.
2. Stir-fry the garlic and ginger first until aromatic, which should take about 30 seconds.
3. Next, toss in the onions and cook until slightly translucent.
4. Add the bell peppers (and other vegetables, if using) and stir-fry for 2-3 minutes. The vegetables should remain crisp but cooked.

5: Combine Everything

1. Return the chicken to the pan along with the stir-fried vegetables.
2. Pour the prepared sauce over the chicken and vegetables, ensuring everything is evenly coated.
3. Add the cornstarch slurry and stir the dish until the sauce thickens to your desired consistency.
4. Garnish with chopped green onions and serve immediately.