Creating a Beef Stir-Fry is simple and rewarding. Follow these steps for a delightful dish:

1. Marinate the Beef: In a bowl, combine the sliced beef with 1 tablespoon of soy sauce. Let it sit for about 10 minutes.
2. Prepare the Vegetables: While the beef is marinating, wash and slice the bell pepper, onion, and broccoli. Set all the vegetables aside.
3. Heat Oil: In a large skillet or wok, heat 2 tablespoons of vegetable oil over medium-high heat.
4. Cook the Beef: Add the marinated beef to the skillet, spreading it out so it cooks evenly. Stir-fry for about 2-3 minutes until browned. Remove the beef from the skillet and set it aside.
5. Sauté Vegetables: In the same skillet, add a bit more oil if needed, then toss in the sliced onion, garlic, and ginger. Stir-fry for 1 minute until fragrant.
6. Add Remaining Vegetables: Add the bell pepper, broccoli, and snap peas to the skillet. Stir-fry for an additional 3-4 minutes until the vegetables are tender but still crisp.
7. Combine Everything: Return the cooked beef to the skillet with the vegetables. Stir to combine.
8. Make the Sauce: Pour in the 3 tablespoons of soy sauce and the oyster sauce. Stir well. Then, add the cornstarch mixture to thicken the sauce. Continue to cook for 1-2 minutes until the sauce has thickened and everything is well-coated.
9. Serve: Remove from heat and serve hot over cooked rice or noodles.

With these straightforward steps, you can create an astounding Beef Stir-Fry that is not just delicious but also a colorful display of culinary excellence.