Flank Steak Fajitas Recipe

Marinated flank steak and loads of flavorful veggies make a delicious fajita filling perfect for busy weeknight dinners. Tastes great and easy to make! This Flank Steak Fajitas recipe is one of our go-to meals!

Flank Steak Fajitas Recipe close up picture of fajita filling wrapped in warm tortilla
What is Flank Steak
Flank Steak is Keto & Budget-Friendly too!
High in protein and low carb, flank steak is perfect for a low carb, keto lifestyle. It is also a budget friendly cut of beef, and the leftovers are easy to use in other recipes such as these Flank Steak Fajitas or stir fry, making flank steak a smart choice when meal planning. Note: Use low carb tortillas to keep carbs in check for this flank steak fajitas recipe.
Flank Steak Fajitas Recipe – flank steak and veggies in cast iron skillet ready to eat
What is the best way to cook flank steak?
Although flank steak can be cooked many different ways, I prefer to marinate and cook flank steak quickly with high heat in a cast iron skillet similar to my Cast Iron Chicken Breast recipe. Grilling marinated flank steak with high heat is another tasty way to cook it. Visit my Cast Iron Flank Steak recipe for great tips to cook flank steak perfectly every time.

Flank Steak Fajitas Recipe – flank steak and vegetables in cast iron skillet ready to enjoy
How To Make Flank Steak Fajitas
While fajitas are more commonly made with skirt steak, flank steak is a more economical cut of beef and a wonderful alternative to skirt steak. Because flank steak is so lean, it is best to marinate before cooking. Although there are several ingredients in my flank steak marinade, it really only takes a few minutes to whisk the ingredients together. It’s totally worth it as the flavor really does come through and compliments the flank steak nicely.

The acid in the marinade helps to tenderize the flank steak, and the oil in the marinade means you don’t have to oil the cast iron skillet when cooking the flank steak.
Marinate the flank steak for at least 30 minutes and up to 8 hours. The longer the better. I like to whisk up the marinade first thing in the morning so the flank steak can marinate all day.
Place marinated flank steak in hot skillet and sear for about 5 minutes on each side. Remove from heat to rest while making the veggies.
In same skillet, melt 1 tbsp butter on medium heat & add 1 pint sliced mushrooms with a pinch of salt. Cook mushrooms until softened.
Then add remaining sliced vegetables. Cook over medium heat until veggies are cooked to your liking. Taste the vegetables and add more salt as needed.
Slice flank steak thinly against the grain & add to skillet with the veggies. Don’t forget to toss the meat drippings in too. No flavor down the drain!
Serve with warmed flour tortillas, fresh tomatoes, lime wedges, guacamole, & sour cream.

FLANK STEAK FAJITAS
Marinated flank steak and loads of flavorful veggies make a delicious fajita filling perfect for busy weeknight dinners. Tastes great and easy to make! This Flank Steak Fajitas recipe is one of our go-to meals!

INGREDIENTS:
Flank Steak Marinade *
1/2 cup olive oil
3 tablespoons Worcestershire sauce
1/4 cup fresh lime juice (about 2 limes, juiced)
1 tablespoon garlic, minced
1 teaspoon ground cumin
1/2 tablespoon chili powder
1/2 teaspoon red pepper flakes
1 tablespoon sugar
1 teaspoon kosher salt
1/2 teaspoon freshly cracked black pepper
2 lbs Flank Steak (see note 1)
Flank Steak Fajitas
1 pint mushrooms, sliced
2 medium onions, sliced
2 red bell pepper, sliced
1 green bell pepper, sliced
1 yellow bell pepper, sliced
6 Flour tortillas, warmed
Fresh cilantro, chopped for garnish
2 limes, quartered
1 tbsp unsalted butter
Optional Toppings
Fresh tomatoes, diced
Guacamole
Sour cream
INSTRUCTIONS
Flank Steak Marinade
Combine 1/2 cup olive oil, 3 tbsp Worcestershire sauce, 1/4 cup fresh lime juice, 1 tbsp minced garlic, 1 tsp cumin, 1/2 tbsp chili powder, 1/2 tsp red pepper flakes, 1 tbsp sugar, 1 tsp salt, & 1/2 tsp pepper and whisk to combine.
Place flank steak into a gallon sized zip-top bag and pour flank steak marinade into bag. Zip to close tightly. Place bag in refrigerator for at least 30 minutes and up to 8 hours.
Flank Steak Fajitas
Heat a 12-15″ cast iron skillet over mid high heat. Remove flank steak from marinade. Discard marinade.
Place flank steak in hot skillet and sear for about 5 minutes or until a nice crust forms on the one side of the flank steak.
Using tongs, turn flank steak over and sear the other side for about 5 minutes or until cooked to 120°F.
Remove flank steak from skillet and rest 5-10 minutes. Slice thinly across the grain.
While the flank steak is resting, melt 1 tbsp butter on medium heat & add 1 pint sliced mushrooms with a pinch of salt. Cook mushrooms until softened. Then add remaining sliced vegetables. Cook over med. heat until veggies are cooked to your liking. Taste the vegetables and add more salt as needed.
Slice flank steak thinly against the grain & add to skillet with the veggies. Serve with warmed flour tortillas, fresh tomatoes, lime wedges, guacamole, & sour cream.