This Flank Steak Stir Fry is one of my go-to meal recipes when I want a home-cooked meal but don’t feel like cooking. It’s quick and easy to prepare, but it's still full of flavor and delectable textures. I love steak, and this is one of the tastiest ways to prepare it that takes minimal effort.

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The oyster sauce adds umami and savory flavors to the steak and peppers, creating a flavor bomb in every bite. Pair it with rice, pasta, or any of your favorite side dishes to create a stunning meal that fills you up.
If you like beef flank steak recipes, you will love my Slow Cooker Flank Steak and this Smoked Flank Steak.
Why You Will Love This Recipe
- It takes 4 main ingredients: Besides the cornstarch and spices, this stir-fry flank steak only requires beef, onions, peppers, and oyster sauce. It doesn’t get any easier than that!
- It’s ready in less than 30 minutes: It takes less than 30 minutes to prepare, cook, and serve this flank steak stir fry recipe. Then, you can spend more time enjoying the meal with your family instead of in the kitchen.
- It’s easy to customize: Since this is a very basic recipe, it’s easy to customize. Feel free to experiment with the spices and veggies to make it your own.
Ingredients
Below is what I use to make this stir-fry flank steak and veggies. It’s only the beef, onions, peppers, and components for a quick stir-fry sauce that doubles as a flank steak stir-fry marinade if you desire.

- Steak: I love flank steak for this recipe because it doesn’t need a lot of cooking beyond a hard sear. You can still use another variety of beef, like sirloin or skirt steak, to yield a similar result.
- Onion and peppers: I use a yellow or white onion for this recipe and a variety of colors of bell peppers. Choose any kind that you like! I enjoy red, green, and yellow.
- Oyster sauce: This sauce is a salty and sweet umami bomb. It adds so much complexity to the stir fry, which is why I don’t add any other ingredients to the sauce besides salt and pepper.
- Cornstarch: I use a little cornstarch to thicken the sauce right before serving. It helps it perfectly coat all of the steak and veggies.
See the recipe card below for exact ingredient amounts, nutritional information, and detailed instructions.
Variations
- Spicy: Cook some sliced fresh jalapenos with the onions and peppers or add some sriracha or chili sauce to add a bit of heat.
- More veggies: Add cooked broccoli, frozen stir fry mix, sliced green beans, or even some asparagus to pack your stir fry with more vegetables.
- Chicken and peppers: Swap the steak for sliced chicken breast or thighs. Just be sure to adjust the cooking time to fully cook the chicken.
- Add some shrimp: Replace one-third of the beef with raw shrimp. Cook them separately and then add both back in the end of cooking as the recipe directs.
How to Make Stir Fry with Flank Steak
Here are the instructions needed to make this flank steak stir fry recipe. Slice your steak and veggies before you get started so you can just add them when you need to.

Step 1: Make the sauce. Combine the cornstarch, oyster sauce, salt, pepper, and ⅓ cup of water in a small cup or bowl. Whisk it until it’s nice and smooth.

Step 2: Sear the steak. Grab a large skillet and heat it over medium-high heat, and add olive oil. Add the steak pieces and sauté them for about 4-5 minutes, or until all sides are browned. Then, set it aside.

Step 3: Cook the onions. Put your sliced onions into the skillet with more olive oil and let them cook for 3-4 minutes or until tender.

Step 4: Add the peppers. Now, you can add the sliced bell peppers. Cook the onion peppers for an additional 2-3 minutes or until the peppers are tender.

Step 5: Add beef and sauce. Put your seared flank steak strips back into the skillet and pour in the oyster sauce mixture.

Step 6: Stir and thicken. Stir all the ingredients well and let them cook for about 2 minutes to thicken the sauce. Enjoy with your favorite side or over rice!
Recipe Tips
- Trim the steak well: Remove any extra fatty pieces and visible gristle from the steak before you slice it. This ensures that the meat will cook evenly and be super tender. No one wants a tough bite!
- Marinate the steak: Treat the oyster sauce like stir-fried steak marinade and let it marinate before you sear it for even more depth of flavor. This step adds even more complexity to the recipe.
- Pat everything dry: If the meat or veggies are too wet, they will steam rather than sear. This will make them mushy and not get a good crust. Pat the ingredients down with paper towels before you season and cook them.
- Don't overcrowd the skillet: Make sure you use a large skillet so the vegetables and meat have room to move around. This allows them to sear more easily for that charred flavor.
If you love recipes like this steak and peppers, you may also enjoy these Fajita Nachos with Steak.

Storage Directions
- Storing: Store leftovers in an airtight container in the refrigerator for up to 3 days. You may freeze them in a freezer-safe container for up to 2 months.
- Reheating: This flank steak stir fry is best reheated in a skillet on the stove, but you may use the microwave if you’re fine with the veggies being soft.
- Make Ahead: Slice your steak and vegetables up to a day in advance and store them in airtight containers in the refrigerator until you’re ready to cook. I love to do this to save time later!
Serving Suggestions
- Serve this stir-fry steak recipe over coconut rice or plain white rice if you prefer.
- Add some shrimp, like these broiled shrimp skewers, to make a surf and turf meal.
- I like to add more vegetables on the side, and these glazed green beans and carrots or these Mediterranean roasted vegetables are a great addition.
- Try a cold side dish or starter like this cold asparagus salad.

Recipe FAQs
Sure! Preheat the air fryer and cook the steak for 6-8 minutes. Then, swap it for the veggies and air fry them for 5-7 minutes. You can either marinate the ingredients in the oyster sauce and cornstarch or heat them on the stove in a saucepan over medium heat until thick, and toss them before serving.
Excess moisture is the main cause of a soggy stir-fry. Searing the steak over higher heat allows the outside to brown, and it won't do that if it's wet.
If your heat isn’t high enough, your ingredients will stick to the pan. Stir-frying is done quickly over a higher temperature, and if the heat is too low, the steak and veggies will stick and not cook properly.

More Delicious Stir-Fry Dishes
Do you like stir-fry recipes? Here are some recipes you may also like to try.
If you try this recipe and love it please leave a star rating in the recipe card below or even better, drop a review in the comment section, I always appreciate your feedback. Be sure to follow along with me on Facebook, Pinterest, and YouTube for more easy recipes!

Flank Steak and Peppers Stir Fry
Equipment
Ingredients
- 1 pound flank steak cut into strips, or any cut beef steak or boneless, skinless chicken breast, sliced
- 1 medium onion sliced
- 2 large bell peppers green, yellow, orange or red, thinly sliced
- ¼ cup oyster sauce
- 1 tablespoon cornstarch
- ¼ teaspoon salt
- ¼ teaspoon pepper
- 4 tablespoons olive oil or another vegetable oil
Instructions
- Get out and measure all of your ingredients.
- In a cup mix oyster sauce, ⅓ cup water, cornstarch, salt, and pepper.
- Stir until incorporated and set aside.
- In a large skillet, on medium high heat, place 2 tablespoons of oil until it is shimmering or when flicking a drop of water in it causes it to dance. Add sliced beef or chicken and sauté until browned and, if using chicken, it is no longer pink. Around 4 or 5 minutes. Remove meat and set aside.
- Heat remaining 2 tablespoons of oil over medium high heat until it shimmers or a drop of water flicked in it dances as well. Add onions and stir for a few minutes until tender.
- Then add peppers and stir for a few more minutes until tender.
- Add cooked beef or chicken and oyster sauce mixture.
- Stir to coat and thicken sauce, just a few minutes.
- Serve with rice or noodles. Enjoy!
Notes
- Ensure your pan is nice and hot before you start cooking in it to prevent the steak and vegetables from sticking to the bottom.
- Store extra flank steak stir fry in an airtight container. It will stay fresh in the fridge for up to 3 days.
- Trim as much visible fat and gristle from the steak and be sure to cut it against the grain to prevent tough, chewy bites.
Nutrition
This post was originally published in April 2016. It's been updated with new content and images.
Karla Verdun says
What is the nutritional facts about this recipe
Karin and Ken says
Just added it for chicken. You need for beef too? I’ll see if I can figure out how to add them both. Regardless enjoy this recipe. We think it’s delicious. Hopefully you do too! All the best. Karin
Nancy says
delicious recipe. Thank you for sharing
Karin and Ken says
As always you are most welcome! Happy to hear you enjoy this recipe as much as we do! All the best. Karin
Maurice says
Thanks for the recipe! It was nice and very easy to make. Though I added just a bit of carrot and mushrooms. I like the recipe because its very easy to make. Though I feel with peppers only it needed something else. But that's just a personal preference. Thanks again!
Karin and Ken says
As always you are most welcome. Hopefully you find some other recipes on this site that you enjoy just as much. All the best. Karin