Preparing Beef & Onion Stir-Fry is simple and can be accomplished in just a few steps. Follow these instructions for the best outcome:

1. Prepare the Beef: Thinly slice the beef against the grain and transfer it to a mixing bowl. Add soy sauce, cornstarch, and a pinch of salt and pepper. Mix well and let it marinate for about 10-15 minutes.
2. Heat the Oil: In a large skillet or wok, heat the vegetable oil over medium-high heat until shimmering.
3. Cook the Beef: Add the marinated beef to the pan. Stir-fry for about 3-4 minutes or until the meat is browned and cooked through. Remove the beef from the pan and set it aside.
4. Sauté the Onions: In the same pan, add the sliced onions and cook for 4-5 minutes, stirring frequently until they become soft and slightly caramelized.
5. Add Garlic: Stir in the minced garlic and cook for an additional minute until fragrant.
6. Combine Ingredients: Return the cooked beef to the pan with the onions. Add oyster sauce and water. Mix everything well and cook for another 2 minutes to combine the flavors.
7. Adjust Seasoning: Taste and adjust the seasoning with more soy sauce, salt, or pepper if needed.
8. Garnish: Remove from heat and garnish with chopped green onions.

Following these steps will ensure a delicious Beef & Onion Stir-Fry every time you prepare it, impressing your family and friends with your culinary skills.