This black pepper beef stir-fry is everything you want in a weeknight dinner: fast, deeply flavorful, and loaded with tender beef, crisp-tender green beans, and savory mushrooms. Thin slices of flank steak are briefly marinated in a simple but powerful mixture of soy sauce, cornstarch, tangy rice vinegar or lime juice, sugar, and plenty of coarse black pepper. Then everything is cooked quickly over high heat so the vegetables stay vibrant and the beef remains juicy and tender. Served over hot jasmine rice or noodles, it tastes like your favorite takeout, but fresher and brighter.
Ingredients
For the Stir-Fry:
- ¾ pound flank steak, trimmed and thinly sliced
- 1 pound fresh green beans, ends trimmed and snapped into 2–3 inch pieces
- 1 cup mushrooms, sliced (button or cremini)
- 1 medium onion, thinly sliced
- 2 slices fresh ginger, unpeeled
- 3 tablespoons canola oil, divided
- ¼ cup water
- Salt, to taste
For the Marinade:
- 2 tablespoons soy sauce
- 1 tablespoon cornstarch
- 1 tablespoon rice vinegar or lime juice
- 1 teaspoon sugar
- 2 teaspoons coarse black pepper
Optional finishing touches (all mentioned in the original recipe as ideas):
- Drizzle of sesame oil
- Red pepper flakes
- Toasted sesame seeds or sliced green onions for garnish
Prep Time: 15 minutes
Cook Time: 15 minutes
Total Time: 30 minutes
Servings: 4
Approximate Calories: ~320 kcal per serving
Instructions
1. Prepare all the ingredients
Before you turn on the stove, get everything ready so the cooking can move quickly.
- Start with the green beans: rinse them well under cold water, pat them dry, then trim off the stem ends. Snap them into 2–3 inch pieces so they are easy to eat and cook evenly.
- Clean the mushrooms and slice them into even pieces; not too thick, so they brown lightly, and not too thin, so they don’t disappear during cooking.
- Peel the onion, cut it in half from root to tip, then slice it into thin half-moons. These will soften and lightly caramelize in the wok.
- Cut the flank steak by first slicing with the grain into strips about 2 inches wide. Then slice each strip across the grain into very thin slices, about ⅛ inch thick. Slicing across the grain is essential for tender, easy-to-chew pieces of beef.
- Set aside the two unpeeled slices of fresh ginger; they will be added whole to perfume the stir-fry and removed later.
Having everything prepped and arranged near the stove will make the actual stir-frying smooth and stress-free.
2. Marinate the beef
- In a medium bowl, whisk together the soy sauce, cornstarch, rice vinegar or lime juice, sugar, and coarse black pepper until the cornstarch is fully dissolved and the mixture looks smooth.
- Add the sliced beef to the bowl. Use your hands or tongs to turn and massage the slices so every surface is coated with the marinade.
- Let the beef rest in the mixture for 10–15 minutes while you tidy up and get the pan ready. This short marination time is enough to season the meat, help tenderize it, and create a glossy texture once it hits the heat.
3. Cook and steam the green beans
- Place a large wok or wide skillet over high heat and let it heat up thoroughly. Add 1 tablespoon of canola oil and swirl it around to coat the bottom.
- Add the green beans to the hot oil. Stir-fry them for about 1 minute, tossing frequently so they blister slightly in spots and take on a bright, glossy appearance.
- Pour in the ¼ cup of water, then quickly reduce the heat to medium. Cover the wok or pan with a lid. Let the beans steam for 6–8 minutes, lifting the lid once or twice to stir, until they are tender-crisp: easily pierced with a fork, but still slightly firm and vibrant green.
- When done, remove the green beans with any remaining liquid and set them aside on a plate or in a bowl.
Steaming after a brief stir-fry keeps the beans crisp yet cooked through, with great color and texture.
4. Sauté the aromatics, mushrooms, and onion
- Turn the heat back up to high and add another tablespoon of canola oil to the wok.
- Drop in the ginger slices and stir-fry them for about 30 seconds, just until fragrant. They will release a warm, spicy aroma into the oil that will permeate the whole dish.
- Add the sliced onion and mushrooms to the pan. Stir-fry for 2–3 minutes, constantly moving them around so the onions soften and turn slightly translucent while the mushrooms release their moisture and begin to brown at the edges.
- Once the vegetables are softened and lightly golden, carefully remove the ginger slices and discard them so no one bites into them later.
5. Stir-fry the marinated beef
- Add the remaining 1 tablespoon of canola oil to the hot wok.
- Spread the marinated beef slices in an even layer across the surface. Let them sear for a brief moment before you start stirring; this encourages a bit of browning.
- Stir-fry the beef for 2–3 minutes, turning the pieces constantly so they cook quickly and evenly. The slices should change from raw red to browned with no visible pink, but still look juicy and tender rather than dry.
The combination of high heat, thin slices, and the cornstarch in the marinade helps the beef develop a glossy, flavorful coating.
6. Combine everything and finish the dish
- Return the cooked green beans to the wok, along with the sautéed onions and mushrooms.
- Toss everything together, lifting and turning with a spatula or tongs so the sauce clings to the vegetables and beef. Stir-fry for another 1–2 minutes, just until everything is heated through and well combined.
- Taste the stir-fry and add salt if needed. You can also add a little more coarse black pepper at this stage to emphasize the peppery bite.
If you like, finish with a light drizzle of sesame oil and a pinch of red pepper flakes for extra depth and gentle heat, plus a sprinkle of toasted sesame seeds or sliced green onions for a touch of crunch and color.
7. Serve
Serve the black pepper beef, mushroom, and green bean stir-fry immediately while it is piping hot. Spoon it over bowls of steamed jasmine rice or nestle it on top of noodles so the savory sauce can soak in. Each bite combines tender strips of beef, crisp-tender beans, and meaty mushrooms, all wrapped in a fragrant, pepper-forward glaze that makes this dish satisfying, elegant, and perfect for any busy evening.