1 lb (450 g) flank steak or sirloin, thinly sliced against the grain
2 tablespoons vegetable oil
1 large onion, thinly sliced
1 red bell pepper, sliced
1 green bell pepper, sliced
2 cloves garlic, minced
1 teaspoon fresh ginger, grated (optional)
For the Sauce
1/4 cup soy sauce
2 tablespoons oyster sauce
1 tablespoon hoisin sauce
1 teaspoon cornstarch
1/2 teaspoon black pepper
1/2 teaspoon sugar
1/4 cup beef or chicken broth
1 teaspoon sesame oil (optional)
For Serving
2 cups cooked white or brown rice
Chopped green onions for garnish
Instructions
Prepare the Sauce : In a small bowl, whisk together soy sauce, oyster sauce, hoisin sauce, cornstarch, black pepper, sugar, and broth until smooth. Set aside.
Cook the Beef : Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat. Add the sliced steak and stir-fry for 3–4 minutes until browned but not overcooked. Remove from skillet and set aside.
Cook the Vegetables : In the same skillet, heat the remaining tablespoon of oil. Add onions and bell peppers and stir-fry for 4–5 minutes until crisp-tender. Add garlic (and ginger if using) and stir-fry for an additional 30 seconds until fragrant.
Combine Beef and Sauce : Return the beef to the skillet with vegetables. Pour the prepared sauce over the beef and vegetables. Stir-fry for 2–3 minutes until sauce thickens and coats all ingredients evenly. Drizzle with sesame oil if desired.
Serve : Serve the pepper steak over cooked rice. Garnish with chopped green onions.