Creating Pepper Steak with Bell Peppers and Onion is a delightful process. Follow these simple steps to ensure success:

1. Marinate the Beef: In a bowl, combine sliced flank steak, soy sauce, and cornstarch. Toss to coat evenly and set aside.
2. Heat the Oil: In a large skillet or wok, heat the vegetable oil over medium-high heat until hot.
3. Cook the Beef: Add the marinated beef to the skillet in a single layer. Cook until browned and nearly cooked through, about 3-5 minutes. Remove and set aside.
4. Sauté the Vegetables: In the same skillet, add sliced bell peppers and onions. Sauté until they begin to soften, about 3-4 minutes.
5. Add Aromatics: Stir in the minced garlic and ginger. Cook for an additional 1-2 minutes until fragrant.
6. Combine Ingredients: Return the beef to the skillet. Stir in oyster sauce, brown sugar, black pepper, and red pepper flakes if using. Cook for another 2-3 minutes until everything is heated through and well combined.
7. Serve over Rice or Noodles: Once everything is mixed and cooked to your liking, serve the pepper steak hot over a bed of cooked rice or noodles.

These steps will guide you in creating this incredible dish that will leave your taste buds wanting more!