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Not only do these Flank Steak Fajitas make for a quick-and-easy weeknight meal, but they’re also a fun way to let you and the family take a more ‘hands on’ approach to eating! I like to serve them buffet style and let everyone build their own fajita.

Maybe with a side of oven-baked fries? Maybe some cauliflower rice? You’re the boss, applesauce!

Flank Steak Fajitas Whole30 Paleo Primal Gourmet Easy Recipe

Flank Steak Fajitas Whole30 Paleo Primal Gourmet Easy Recipe

To keep things Whole30 and Paleo friendly, consider wrapping the flank steak fajitas in leaves of fresh Boston lettuce. Much like my lettuce-wrapped Greek burgers, I actually prefer my fajitas this way. But if you want to exercise your Food Freedom and dabble in some flour tortillas, go for it! Just be sure to serve with guacamole, your favourite salsa (I’m a Herdez salsa verde guy myself), and some lime wedges for a bit of zing.

Flank Steak Fajitas Whole30 Paleo Primal Gourmet Easy Recipe

As far as the steak goes, I think flank steak works best here. It’s relatively affordable, delicious and usually sold in large flaps that are great for a small family or leftovers. If flank steak is unavailable or you don’t want to cook such a large portion, you can substitute similar cuts like skirt steak, flat iron, or even top sirloin.

Flank Steak Fajitas Whole30 Paleo Primal Gourmet Easy Recipe

In case you need a few pointers for grilling your flank steak, I’ve put together a few of my top tips here

It bears repeating that since flank steak and comparable cuts can be fairly tough, they should ideally be cooked to a medium-rare or medium doneness, which usually clocks in at an internal temperature of between 135-145F respectively.

For best results, get yourself a digital meat thermometer like this Lava Tools Javelin (I’ve had mine for years and it’s great).

Flank Steak Fajitas Whole30 Paleo Primal Gourmet Easy Recipe Flank Steak Fajitas Whole30 Paleo Primal Gourmet Easy Recipe

If I had my choice, I would only cook these Flank Steak Fajitas over a charcoal grill. It will give you the most flavourful finished product. However, if you live in an apartment or just can’t bear to grill in sub-zero temperatures during the winter months, than a cast-iron grill pan is the way to go.

You can either cook the veggies in the same grill pan you use to cook the steak (which is what I do because I don’t want to wash extra pans), or you can sauté them in a separate skillet. If going the former route, I suggest rinsing out the skillet after cooking the steak since you will likely have some burnt bits that can make the peppers bitter.

Flank Steak Fajitas Whole30 Paleo Primal Gourmet Easy Recipe

The best bang-for-your-buck grill pan is undoubtedly this Lodge model. It’s affordable and built to last. It will need some seasoning an maintenance but the process is easier than you think. See here for my guide to Seasoning Cast-Iron.

If, on the other hand, you are looking for an enamel-coated, cast-iron grill pan, one that does not require seasoning or maintenance, than this Staub model is excellent. It’s expensive, yes. But you get what you pay for and if I’m not mistaken, it was just ranked best-in-class by America’s Test Kitchen, which is no small feat.

One last thing before I forget: I like to add a tiny bit of agave nectar to the flank steak marinade. The sweetness balances the acidity from the lime juice. However, you can absolutely omit if doing a round of Whole30. I promise, it will still be delicious!

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Flank Steak Fajitas - Whole30, Paleo

These Flank Steak Fajitas make for a quick-and-easy weeknight meal and are a fun way to let you and the family take a more ‘hands on’ approach to eating!
Prep Time: 15 minutes
Cook Time: 20 minutes
Total Time: 35 minutes
Servings: 4 people


  • 1 lbs flank steak
  • 1 red bell pepper – julienned
  • 1 green bell pepper – julienned
  • 1 yellow bell pepper – julienned
  • 1 jalapeño pepper – seeded and julienned, optional
  • 1/2 red onion – julienned
  • 1 tbsp avocado oil
  • kosher salt

For marinade:

  • ¼ cup avocado oil
  • ¼ cup fresh cilantro
  • 1 lime – juiced
  • 2 cloves garlic – smashed
  • 1 tsp ground cumin
  • 1 tsp ground coriander
  • 1 tbsp agave nectar, optional or omit for Whole30

for Serving:

  • 2 heads Boston lettuce
  • Salsa Verde
  • Lime wedges
  • Guacamole


  • Add all marinade ingredients to a mason jar and pulse with an immersion blender until combined yet chunky. Alternatively, use a food processor.
  • Poke one side of the flank steak with a fork. Season both sides with salt and transfer steak to a zip-top bag. Pour in all of the marinade, massage everything to coat, squeeze out all of the air in the bag and refrigerate 1-4 hours.
  • When ready to cook, preheat a grill or grill pan to high heat. Remove steak from marinade and brush off any excess liquid. Lay flat on grill pan and cook 5-6 minutes per side or until the thickest part of the steak reads 135F on a meat thermometer. Transfer cooked steak to a board and let rest 10 minutes before slicing.
  • Wipe down grill pan, add 1 tbsp avocado oil along with all of the bell peppers, jalapeño and onion. Season with a pinch of salt and grill until softened, tossing regularly (approximately 8-10 minutes).
  • Slice flank steak against the grain and serve with leaves of Boston lettuce, lime wedges, salsa, guacamole and grilled veggies.
Tried this recipe? Leave a comment below!

About the Author

Hi, i'm Ronny! In 2013, after a lifetime of struggling with my weight and body issues, I rehabilitated my relationship with food, lost over 40 pounds and completely changed my life.

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Recipe Rating


  1. Best flank steak I have ever had! I can’t wait to try more of your recipes! Thanks for an amazing dinner that even my picky toddler yummed up.