Flank Steak Fajitas | Sheet Pan Keto Fajitas

Mix things up this Taco Tuesday with these delicious and keto-friendly Flank Steak Fajitas! They're the easiest flank steak fajitas you can make and oh-so-delicious!

What Makes These Flank Steak Fajitas So Awesome?

• Fast. This delicious sheet pan recipe will have dinner on the table in under 30 minutes.
• Easy. Throw all of the ingredients on a pan and bake. That's it.
• Low Carb. No guilt with these fajitas. There are only 6 net carbs per serving.
• Gluten-Free. Forget worrying about finding the perfect tortilla substitute for your family with gluten allergies. Just skip the shell completely!

Most of us are well aware of how delicious fajitas can be with all their flavor and fun variations. However, a lot of people don't know how easy they are, even easier than tacos if you can believe it. They're easy to customize with your favorite toppings and ingredients, just like tacos are.

What makes these Flank Steak Fajitas so easy is the fact that they're not made in the traditional manner in a skillet. The vegetables and meat are cooked at the same time on a baking sheet in the oven.

This means once you chop it all, you just have to toss it onto the pan, throw it in the oven, wait for them to cook, and dinner is ready.

How Do You Tenderize Fajita Meat?

The best way to make fajita meat tender is to marinate it so the acidity starts to break down the fibers in the meat. That's why I have you marinate the flank steak as you're prepping your veggies to bake.

The meat will take a little marinating. However, I have the perfect fajita spice mix for your Flank Steak Fajitas that contain spices you are sure to be familiar with. If you've never made your own fajita spice mix, you're missing out.

Ditch the store-bought mix and throw together your own mix to make the tastiest Keto Steak Fajitas you've ever had.

Can I Have Fajitas On Keto?

You absolutely can have fajitas on a keto diet. However, they may not be what you traditionally think of as fajitas.

Corn and flour tortillas can be quite high in carbs, so it's best to skip those if you want to stay in ketosis. There are some yummy low carb tortillas on the shelves of grocery stores now, but they should be consumed in moderation.

My recommendation would be to let the flavors of the low carb ingredients (or traditional fajita filling) be the star of the show and skip the tortillas altogether. These Keto Steak Fajitas are so good you won't even miss the carbs.

Flank Steak Fajita Ingredients

Flank Steak Spice Mix

• Ground Cumin
• Ancho Chile Powder
• Ground Coriander
• Onion Powder
• Kosher Salt

For The Fajitas

• Garlic Powder
• olive oil, or coconut oil
• Lemon Juice
• Flank steak
• Onions, chopped
• Bell Peppers
• Jalapeño Peppers
• Lettuce leaves

Watch a Video on How to Make a Great Keto Steak Fajita

How To Make Flank Steak Fajitas

1. Spray a 13 x 9-inch baking sheet with a keto-friendly cooking spray and set aside. Turn on your broiler and move an oven shelf to the highest position in the oven. 

2. While your oven heats, place the flank steak into a large bowl. Add in the flank steak, 2 tablespoons of oil, lemon juice, and the Spicy Meat rub. Mix well with your hands, turning the flank steak to coat it in the marinade. Set aside and let this marinate while you chop the vegetables.

3. Place chopped vegetables on the prepared sheet pan (Why dirty another bowl, am I right?) Pour 1 tablespoon of oil over the vegetables. Add 1 teaspoon of salt. Use your hands to mix the vegetables with the oil, squishing lightly to macerate the vegetables. Move the vegetables onto one side of the sheet pan, spreading them in one thin layer.

4. Place the marinated flank steak on the other side of the sheet.

5. Broil for 6-8 minutes. Check the flank steak with a meat thermometer (135F for medium rare). If the steak is ready, use a set of tongs to remove it to a plate. Cover the plate and allow the steak to rest for 10 minutes.

6. Meanwhile, toss the vegetables with the tongs, and broil for another 2-3 minutes. Remove the vegetables to a serving dish.

7. Slice the meat on the bias into thin slices. Serve the meat and vegetables either by themselves or on lettuce leaves for wrapping.

Expert Tips For Making Flank Steak Fajitas

• You can turn this (or the leftovers) into a salad by adding a little of the spice rub seasoning to a mix of equal parts of mayo and sour cream for dressing.
• Do not overcook the flank steak or it will get dry and rubbery. If in doubt, undercook it a bit and let it sit under foil so that it can finish cooking.
• The vegetables take longer to cook so remove the steak to allow the veggies to cook.

What Are Good Toppings For Fajitas?

With any fajitas, the meat is the star of the show. With the delicious marinade you use for the flank steak in this recipe, that is definitely the case.

That being said, you can take your Keto Fajitas up a notch with some delicious toppings. You've already cooked the peppers and onions along with the fajita meat, but here are a few other low carb ingredients that might make for a perfect keto meal:

• Cheese
• Sour Cream
• Avocado
• Lettuce
• Cauliflower Rice
• Tomatillo Salsa
• Avocado Tomatillo Salsa

How Long Do They Last?

For best results, enjoy these flank steak fajitas within 4-5 days of preparing them. You may be able to stretch them a day or two longer if you cook the flank steak a few days before the "use by" date on the package.

What Do You Serve With Flank Steak Fajitas?

Flank Steak Fajitas pair well with anything that you would normally serve with tacos or Mexican food in general. Beans or rice are my preferred sides if I'm not watching my carbs that day.

Here are some great recipes you can make along with the fajitas:

• What's a Mexican food night without refried beans? These Pressure Cooker Refried Beans are so delicious and simple, you'll never want to buy canned refried beans again.
• Make my Mexican Rice Recipe (or Arroz a la Mexicana) in your instant pot or pressure cooker in just one easy step!
• Looking for a great keto appetizer to go with your fajitas? Check out my Low Carb Queso Fundido. It's a delightfully cheesy dip that's to die for!
• Steak Quesadillas are a quick and easy way to please the whole family.

And if you're looking for more great flanks steak recipes, check out my Air Fried Beef Satay.

So the next time you're cooking for Mexican food night, put away that ground beef and make some delicious Flank Steak Fajitas instead. Don't forget to let me know if you enjoyed them in the comments!

Don't forget to check out my other Keto cookbooks.

Keto Instant Pot, Keto Fat Bombs, Sweets, & Treats, and Easy keto in 30 minutes.