This beef, onion, and mushroom stir-fry over rice is a simple yet deeply flavorful dish that comes together quickly while still delivering a comforting, homemade feel. Thin slices of beef are lightly marinated to stay tender, then stir-fried with sweet onions and juicy mushrooms until everything is coated in a glossy, savory sauce. Served over warm white rice, this dish is satisfying without being heavy and works perfectly as a fast lunch or an easy weeknight dinner.
The balance of textures is what makes this stir-fry so appealing. The beef remains soft and juicy, the onions become mellow and slightly sweet as they cook, and the mushrooms absorb all the savory flavors while adding a pleasant earthiness. The sauce, made with soy sauce, oyster sauce, ketchup, and a touch of broth or water, thickens just enough to cling to every bite without overpowering the ingredients. Finished with fresh green onions, the dish feels complete, simple, and well-rounded.
Time and Yield
- Prep Time: 15 minutes
- Cook Time: 12 minutes
- Total Time: 27 minutes
- Servings: 2
Ingredients
- 7 ounces beef steak, thinly sliced
- 8 ounces mushrooms, sliced
- 2 large brown onions, cut into wedges
- 1 tablespoon plus 1 teaspoon cooking oil
- 1 tablespoon plus 1 teaspoon oyster sauce
- 1 tablespoon soy sauce
- 2 teaspoons ketchup
- 2 tablespoons beef broth or water
- 1 teaspoon cornstarch
- 1/2 tablespoon cold water
- Salt and black pepper, to taste
- Cooked white rice, for serving
- 2 green onions, sliced
Instructions
- Prepare and marinate the beef.
Place the thinly sliced beef steak into a medium bowl. Add 1 teaspoon of cooking oil, 1 teaspoon of oyster sauce, 1 teaspoon of cornstarch, and 2 tablespoons of beef broth or water. Mix thoroughly until all the beef slices are evenly coated. This brief marinade helps protect the beef during high-heat cooking, keeping it tender and giving it a light, silky texture once cooked. Set the bowl aside while you prepare the remaining components. - Prepare the stir-fry sauce.
In a separate bowl, combine the soy sauce, the remaining 1 tablespoon of oyster sauce, and the ketchup. In a small cup, mix the cold water with any remaining cornstarch until completely smooth, then add it to the sauce mixture. Stir well to ensure there are no lumps. Having the sauce ready before cooking is essential, as stir-frying moves quickly and timing matters. - Heat the pan and cook the onions.
Heat 1 tablespoon of cooking oil in a large skillet or wok over medium-high heat. Once the oil is hot, add the onion wedges. Cook them while stirring frequently, allowing the onions to soften and become slightly translucent. Let some edges lightly brown, which enhances their natural sweetness and builds a deeper base flavor for the dish.
- Add and cook the mushrooms.
Add the sliced mushrooms to the pan with the onions. Continue cooking over medium-high heat, stirring often. At first, the mushrooms will release moisture. Allow this liquid to cook off so the mushrooms become tender and lightly browned rather than watery. As they cook, they will absorb flavor from the onions and the hot pan. - Cook the marinated beef.
Push the onions and mushrooms slightly to one side of the pan to make space. Add the marinated beef in an even layer. Let it sear briefly without stirring so it develops color, then stir and toss to cook the beef evenly. Because the beef is thinly sliced, it will cook very quickly. Avoid overcooking to keep it tender. - Add the sauce and thicken.
Stir the prepared sauce once more, then pour it into the pan. Toss everything together so the beef, onions, and mushrooms are evenly coated. Continue cooking while stirring gently as the sauce heats and thickens. The cornstarch will activate, creating a glossy sauce that clings to the ingredients without becoming too thick. - Season and serve.
Taste the stir-fry and season with salt and black pepper as needed. Spoon the hot stir-fry over freshly cooked white rice. Finish with sliced green onions sprinkled on top for a fresh, mild bite and a bit of color. Serve immediately while hot.
Helpful Tip
For the most tender texture, always slice the beef against the grain and cook it quickly over high heat. This ensures the meat stays juicy and soft while still developing good flavor.
This beef, onion, and mushroom stir-fry over rice is proof that a short ingredient list can still create a rich and satisfying meal when each step is handled with care.