Best Flank Steak Fajitas

Sizzling Flank Steak Fajitas that rival your favorite restaurant’s… coming right up! The key to this recipe is two-fold: creating a flavor-packed marinade with a few secret ingredients and then letting the beef marinate in it for hours. The result? Juicy, tender steak that’s ready to be loaded up into tortillas with fajitas veggies, guac, and salsa!

Having lived in San Antonio for four years and in Texas all my life, Mexican food holds a special place in my heart. Anytime I try a new restaurant, I always go for one thing: the steak fajitas. To me, the quality of a restaurant often comes down to how they make this dish.

When I moved from San Antonio to Austin, I struggled to find a new favorite spot. So, I decided to learn how to make steak fajitas at home.

After quite a bit of tweaking and recipe testing, I was able to crack the fajita code. There are a few key tips you need to know to make fajitas that rival your favorite restaurants’.

Tips for Making Restaurant-Quality Steak Fajitas

• Marinade, marinade, marinade – that’s where the magic happens! My secret blend includes a dash of both soy sauce and Worcestershire for an irresistible umami kick. (No MSG here!)
• Give it time to soak up all that flavor. Unlike chicken, steak can handle a long marinade without losing its texture. I recommend letting your flank steak bathe in those delicious flavors for a good 6-8 hours — trust me, it’s worth the wait!
• Flank steak is the best cut of beef to use. It strikes the perfect balance between leanness and juiciness, ensuring your fajitas are tender without being greasy.
• And last but not least, don’t let all that flavor go to waste by slicing in the wrong direction – look for those subtle lines and cut opposite to them, or against the grain, for the most tender meat.

Specific Notes About Ingredients

• Beef. This is a huge determinant of how tender or tough the fajitas will come out. Make sure you get a cut that is no thicker than 1 inch for the best results. Flank Steak is very lean, which means it is also on the tougher side. It comes from the lower chest and abdominal muscles of the cow. Make sure to slice flank steaks against the grain. Flat Iron Steak is a very tender portion of the cow. It’s incredibly flavorful, due to the higher amounts of fat marbling throughout. Skirt Steak is the toughest of the three; this cut is from the diaphragm muscle and has a fibrous texture. However, this lean cut of meat has incredible flavor. Marinate it well and slice thin for best results.
• Vegetables. The classic bell pepper and onion combo is my go-to. Feel free to add in some mushrooms, zucchini, or squash, too!
• Taco Seasoning Mix. Homemade taco seasoning or fajita seasoning are the best, but store bought will also work if you’re pressed for time.
• Honey. Pure maple syrup, agave nectar, or even a reduced amount of liquid stevia extract can be used as well.
• Soy Sauce. This gives the perfect saltiness and umami flavor. Gluten-free soy sauce, or tamari, have both been tested in this recipe. Substitute for reduced sodium if needed.
• Worcestershire sauce. Seemingly insignificant, but this gives a TON of flavor! Make sure you look for a gluten-free variety if you are Celiac as some may have hidden wheat.
• Lime Juice. Definitely the best citrus to use, but lemon or orange juice can also be substituted.

How to Make Flank Steak Fajitas

Please see the recipe card below for more detailed ingredient amounts.

1. Mix Together the Fajita Marinade

Whisk together the marinade ingredients in a large bowl. Add steak and let it sit for at least 4 hours, ideally 6-8 hours, or up to overnight in the refrigerator. The longer it marinates, the more flavorful and tender the beef will be.

2. Cook the Fajita Veggies

Sauté sliced bell peppers and onions in oil in a cast-iron skillet over medium-high heat until slightly charred. You want them to be tender yet still crisp. Remove from the skillet and set aside until ready to serve.

You can also use a regular stainless steel skillet. However, if you go with nonstick you won’t get that same char.

3. Sear Flank Steak in Cast-Iron Skillet

Cook steak over medium to medium-high heat for 4-5 minutes per side, or until cooked to your desired doneness. Let any excess marinade drip off the steak before adding it to the skillet.

Check with a meat thermometer for doneness. A temperature of 130-135°F is medium-rare, 140°F is medium.

4. Slice Steak Fajitas Against the Grain

Let steak rest on a cutting board for 5 minutes before slicing. This resting time will help keep all of the delicious juices in.

Cut steak into thin ¼- to ½-inch slices against the grain.

Topping Ideas for Steak Fajitas

Serve on a corn tortilla or make a rice bowl with additional cilantro, sour cream, tomato salsa, and guacamole!

You can also choose pico de gallo, refried black beans, or Chipotle fajita veggies.

FAQs

What to Serve with Steak Fajitas?

There are so many incredible side dishes or dips you can serve with these flank steak fajitas to complete the meal. Here are a few of the best Mexican side dishes:

• Mexican Street Corn Salad
• Easy Guacamole Recipe
• Homemade Salsa Recipe
• Mexican Rice
• Avocado Corn Salad
• Tomatillo Salsa Verde
• Cilantro Lime Rice
• Chipotle Fajita Veggies
• Baked Tortilla Chips
• Instant Pot Black Beans