1.In a bowl, mix the soy sauce, oyster sauce, rice vinegar, and cornstarch. Add the steak slices and toss to coat. Let it marinate for 10-15 minutes.
2.Heat a large skillet or wok over medium-high heat. Add the vegetable oil and swirl to coat.
3.Add the marinated steak and cook for 2-3 minutes, stirring occasionally until it begins to brown. Remove the steak and set aside.
4.In the same pan, add the onions, bell pepper, and garlic. Stir-fry for 2-3 minutes until softened.
5.Return the steak to the pan, then add the freshly ground black pepper and salt. Stir everything to combine and cook for another 2-3 minutes.
6.Serve hot, garnished with green onions if desired. Enjoy your sizzling Chinese pepper steak with onions!
