Creating your Garlic Chicken Stir Fry is simple if you follow these easy steps:

1. Prepare the Chicken: Thinly slice the chicken breast against the grain for tender pieces.
2. Marinate (Optional): In a bowl, combine sliced chicken with 1 tablespoon of soy sauce, and let it marinate for about 10 minutes.
3. Heat the Oil: In a large skillet or wok, heat 2 tablespoons of vegetable oil over medium-high heat.
4. Cook the Chicken: Add the sliced chicken to the hot oil, ensuring not to overcrowd the pan. Cook for about 5-7 minutes, stirring frequently, until the chicken is browned and cooked through.
5. Add Garlic: Once the chicken is cooked, add the minced garlic and stir for about 30 seconds until fragrant.
6. Toss in Vegetables: Add the sliced bell pepper, broccoli florets, and onion into the pan. Stir-fry for an additional 5 minutes until the vegetables become tender yet crisp.
7. Incorporate Sauces: Pour in the remaining soy sauce and oyster sauce (if using) while stirring well to coat all ingredients.
8. Thicken Sauce (Optional): If you prefer a thicker sauce, mix cornstarch with 2 tablespoons of cold water, then add it to the mixture, stirring continuously until thickened.
9. Season: Taste and add salt and black pepper as desired for additional flavor.
10. Serve: Once everything is well combined and heated, remove from heat and serve immediately over cooked rice or noodles.
11. Garnish: Sprinkle chopped green onions on top for an extra touch of freshness.

Following these steps will help you create an incredible Garlic Chicken Stir Fry quickly and effortlessly.