← BlogJune 28, 2026

How to Make the Perfect 15 Minute Flank Steak Fajitas

Mexican · Easy · 15 min · 4 servings

dairy-free
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These 15 Minute Flank Steak Fajitas are sizzling, colorful, and packed with bold Tex-Mex flavor. A quick high-heat sear on thin-sliced flank steak with peppers and onions makes this the ultimate fast fajita recipe.

Why this recipe works

This 15 Minute Flank Steak Fajitas recipe has been crafted to deliver restaurant-quality results in your home kitchen. At just 15 minutes from start to finish, it fits perfectly into a busy schedule without sacrificing flavor. Each serving comes in at 370 calories with 34g of protein, making it a balanced choice for any meal.

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What you will need

This recipe uses 6 simple ingredients that you can find at any grocery store:

  • 1.5 lbs flank steak, sliced thin against the grain
  • 2 tbsp fajita or taco seasoning
  • 3 medium bell peppers, mixed colors, sliced thin
  • 1 medium yellow onion, sliced thin
  • 2 tbsp avocado oil, divided
  • 8 small flour or corn tortillas, warmed

Step by step instructions

Step 1: Season the Steak

Toss sliced flank steak with fajita seasoning and 1 tablespoon avocado oil until evenly coated. Slicing thin against the grain is critical for tender steak that cooks fast.

Step 2: Sear the Steak

Heat a large cast iron skillet or wok over the highest heat possible. Add steak in a single layer and sear for 2 minutes without stirring, then toss and cook 1 more minute. Remove steak and set aside.

Step 3: Cook the Peppers and Onion

Add remaining avocado oil to the same hot pan. Add peppers and onion and cook over high heat for 4 to 5 minutes, tossing frequently, until lightly charred and just tender.

Step 4: Combine and Serve

Return steak to the pan with the peppers and toss together for 30 seconds to combine all the flavors. Serve immediately in warm tortillas with your favorite toppings.

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Easy substitutions

Missing an ingredient? Here are some swaps that work perfectly:

  • flank steak → skirt steak or sirloin sliced thin
  • flour tortillas → corn tortillas or large lettuce leaves for low-carb

Common mistakes to avoid

Watch out for these pitfalls that can affect your results:

  • Overcrowding the pan with too much steak at once causing steaming instead of searing
  • Overcooking the peppers so they become completely soft instead of retaining a slight char and crunch

Nutrition facts

Per serving: 370 calories, 34g protein, 18g carbs, 16g fat, 3g fiber.

Ready to cook?

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