Flank Steak Stir Fry (Chinese Pepper Steak Recipe)

This flank steak stir fry is my go-to pepper steak recipe when I want takeout flavor without the takeout wait. You get tender slices of beef, crisp bell peppers, and onions tossed in a rich, glossy black pepper sauce that’s savory, a little spicy, and packed with umami from oyster sauce, soy sauce, ginger, and a splash of Shaoxing wine. The best part is how fast it is, once everything’s sliced, it cooks in under 20 minutes and tastes like a legit restaurant stir fry.

Why You'll Love This Flank Steak Stir Fry

This recipe delivers that perfect beef stir fry texture. Thin-sliced flank steak cooks fast over high heat, stays tender (especially sliced against the grain), and soaks up the sauce without turning chewy. The peppers and onions stay crisp-tender, and the black pepper sauce clings to everything in that glossy, craveable way.

It’s also a true one-pan dinner that feels special but uses simple ingredients you can actually find. Serve it over rice for the classic pepper steak vibe, or over noodles if you want it extra cozy. And the leftovers are unreal, the sauce soaks in even more overnight, which somehow makes it taste better the next day.

Ingredients You’ll Need

For the Beef & Marinade:

• 2 lbs flank steak or skirt steak, thinly sliced against the grain
• 1 tablespoon cornstarch
• 1 tablespoon Shaoxing wine (or dry sherry)
• 1 tablespoon light soy sauce
• 1 tablespoon sesame oil
• 1 tablespoon ginger, minced

For Stir-Frying:

• 4 tablespoon cooking oil
• 1 large onion, sliced
• 1 red bell pepper, sliced
• 1 green bell pepper, sliced

For the Sauce:

• ½ cup oyster sauce
• 1 tablespoon light soy sauce
• 1 tablespoon freshly ground black pepper
• ¾ teaspoon sugar
• ¼ teaspoon salt
• 1 tablespoon cornstarch
• ½ cup water

How To Make Flank Steak Stir Fry

Step 1: Marinate the Beef

Thinly slice the steak against the grain. Mix with cornstarch, Shaoxing wine, soy sauce, sesame oil, and minced ginger. Let it marinate for 10 minutes.

Step 2: Make the Sauce

In a bowl, whisk together oyster sauce, soy sauce, black pepper, sugar, salt, cornstarch, and water until smooth. Set aside.

Step 3: Sear the Beef

Heat 4 tablespoons of oil in a wok over high heat until shimmering. Add beef and sear until browned but still slightly pink inside. Remove and set aside.

Step 4: Stir-Fry the Vegetables

In the same wok, add onions and bell peppers. Stir-fry for 1 minute until just softened but still crisp.

Step 5: Combine Everything

Return the beef to the wok. Stir-fry for another 1–2 minutes until beef is cooked through.

Step 6: Add the Sauce

Pour the sauce mixture into the wok. Stir until the sauce thickens and coats the beef and vegetables evenly.

Step 7: Serve

Garnish with extra freshly ground black pepper and serve hot over steamed white rice.

Pro Tips To Make The Best Chinese Pepper Steak

• Slice the beef thinly: The thinner the strips, the more tender the final dish. Freeze the beef for 20 minutes before slicing to make it easier to cut evenly.
• Marinating makes a difference: Cornstarch helps velvet the beef, while soy sauce and Shaoxing wine tenderize and add depth. Even 10 minutes of marinating improves texture dramatically.
• Cook over high heat: Pepper steak depends on that quick, hot sear. A ripping hot wok gives you caramelized edges and keeps the vegetables crisp.
• Don’t overcook the beef: Remove it while still slightly pink so it stays tender when returned to the wok later.
• Use freshly ground black pepper: It’s the star of this dish. Pre-ground pepper won’t deliver the same aroma or flavor punch.
• Adjust the heat level: For spicier pepper steak, add ¼–½ teaspoon crushed red pepper flakes or a Thai chili while stir-frying the vegetables.
• Velvet the beef for restaurant-quality texture: If you want ultra-soft beef, add ½ teaspoon baking soda to the marinade and rinse off after 10 minutes before cooking. Then continue with the recipe as written.

Flank Steak Stir Fry FAQs

What cut of beef is best for pepper steak?

Flank steak and skirt steak are two of the best options because they cook fast and stay flavorful. The biggest key is slicing thinly against the grain so the beef stays tender instead of chewy.

How do you slice flank steak for stir fry?

Slice it as thin as you can against the grain. A great trick is to freeze the steak for 15 to 20 minutes first, so it firms up and slices cleaner. Cutting against the grain shortens the muscle fibers and makes every bite more tender.

How do you keep flank steak tender in a stir fry?

Thin slices, high heat, and cornstarch are the combo. The cornstarch in the marinade helps protect the beef and keeps it tender, and cooking quickly over high heat prevents it from drying out.

Can I make pepper steak without oyster sauce?

Yes, but the flavor won’t be as rich. Oyster sauce is what gives pepper steak that deep, glossy, takeout-style umami. If you need a substitute, try hoisin sauce (slightly sweeter) or use extra soy sauce plus a pinch of sugar to balance it.

What can I use instead of Shaoxing wine?

Dry sherry is the best substitute and works really well. You can also skip it if needed, but it adds a subtle depth that makes the sauce taste more restaurant-like.

How do I thicken pepper steak sauce?

Cornstarch is what thickens it. Make sure the cornstarch is fully whisked into the water before adding it, and let the sauce simmer for 30 to 60 seconds in the hot pan to turn glossy and thick.

Can I make flank steak stir fry ahead of time?

Yes. You can slice the beef and mix the sauce ahead of time, and keep them in the fridge. For the best texture, cook right before serving, but leftovers keep well and taste great the next day over rice or noodles.

Why is my stir fry watery?

This usually happens when the pan isn’t hot enough, or it’s overcrowded. Cook in batches if needed so the beef sears instead of steaming, and don’t add the peppers until the beef has browned. Also, make sure your veggies aren’t overly wet after washing.

My Final Thoughts

This flank steak recipe with peppers and onions is savory, saucy, and loaded with fresh pepper flavor. It's an easy takeout-style meal that’s ready in minutes. With tender beef, sautéed peppers, and a glossy oyster sauce glaze, it’s the perfect weeknight dinner. Serve it over fluffy white rice and enjoy every bite. Let me know what you think about this recipe by leaving a comment and a review below!

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