Flavorful Flank Steak Fajitas

fajita marinated flank steak

In February, my sister and I went to Santa Fe and took some classes at the Santa Fe School of Cooking – it was an incredible culinary experience – I highly, highly recommend it for a fabulous getaway for any foodie interested in southwest foods.  I learned so much in just a few days – but I heard one thing that shocked and puzzled me. I attended a class called “Fajitas!,” with Chef Susan Anzalone. She said this –

“Never add acid to marinades for meats. NEVER. It will toughen the meat, just like it does in ceviche. Use zest if you want citrus flavor.”

This stunned me, because for years I have used lime juice in fajita marinades – with chicken and flank steak. So, I did some research seeing what some of my favorite chefs recommend for fajita marinades.

Alton Brown, a culinary hero of mine, calls flank steak “the most marinatable hunk of beef there is” in his book I’m Just Here for the Food. But, he does NOT use citrus in his marinade. On Good Eats, he does use lime juice, but says it does NOT tenderize the meat but only adds flavor. (((Hhmmmm . . . OK, Alton, one question:  if you’re not using juice for tenderizing meat but only flavor, why not use ZEST – it’s 1,000 times more flavorful than juice?)))

Some of my favorite magazines – Bon Appetit, Gourmet and Cooking Light – all use lime juice in their marinades, all recommend varying times for marinating.

And the amazing source America’s Test Kitchen (Cook’s Illustrated February 2007) uses lime juice, but sprinkles it on right before cooking. So, obviously ATK does not recommend citrus as a marinade.

I went to some of my favorite food blogs – Simply Recipes uses lime juice as a marinade. Kalyn’s Kitchen uses just a little lime juice during crock-pot cooking. Serious Eats uses lime and orange juices but a very short marinade time.

Now that grilling season is here, I plan on doing more than my share of feasting on fajitas – but I was confused: how to marinate?

I decided that the only solution in the quest for a perfect fajita marinade was  a true “Donna’s Test Kitchen” test: juice vs. marinade. The two marinades I used were identical except one used zest and one used juice.


I marinated two hunks of flank steak  for one hour on the countertop.

I then sprinkled a little lime juice on both hunks of meat and then cooked the two hunks side by side on the grill with the veggies – same temperature, same length of time.

I took off the meat, let it rest about 10 minutes and sliced it.

The clear, not-even-close winner was the ZEST marinated meat. Both hunks were equally tender – because of thin slicing. But, the ZEST marinated meat was by far the most flavorful.


2 chipotle peppers in adobo sauce
Zest from one lime (about 2 teaspoons full)
1/4 red onion, chopped
3 cloves garlic, diced
1 teaspoon cumin
1 teaspoon kosher salt
1/4 cup extra virgin olive oil

Place all ingredients in a blender and blend until smooth. Place in a zip lock bag with one flank steak (about 1 1/2 pounds). Let stand on counter 1 hour, turning occasionally. ( You can marinate in the fridge overnight – I tried both ways with the same results.)

Remove meat from bag, wiping excess marinade off. Spray both sides of meat with oil.

Grill meat over very high heat for 3 to 5 minutes on each side according to desired doneness. Remove meat from grill and let stand 10 to 15 minutes. Slice very thinly across the grain. Serve with grilled veggies and tortillas.


— posted by Donna


  1. Todd says

    Donna, I just finished preparing your marinade with a personal twist. I have always enjoyed cooking and have been interested in taking a class like you have described. I’m unable to get away to take the class now, so until then I will rely on people like you for questions. My question to you is…why make a marinade with zest, spices, oil, etc. and wipe away the excess prior to cooking? Is this something you learned about or just a recommendation? It seems like something you would want to cook into the meat? Am I wrong here? Thanks! I’m anxious to try the fajitas tomorrow! Getting ready for the first Texas A&M game tomorrow! Whoop!

    • says

      Great thought, Todd. I guess the reason I suggest removing the marinade is to help get a char on the meat – if it’s too wet from the marinade, it is more likely to steam than brown. If you do cook this as you suggest, please come back and let me know how it turned out. I am always happy to learn!

  2. covert critic says

    Since Karen revived the comments, I’d like to add my 2 cents. Steak was well seasoned, not overwhelming like other marinades I’ve tried. This allowed the meat and veggies to compliment each other. Made for a well-balanced and flavorful fajita.

  3. Karen says

    We used skirt steak and chicken with this marinade and were really pleased with the results! Our dinner guests needed to postpone to one day later, so the meat marinated for an extra day! Didn’t seem to hurt either meat, in fact, it might have made it better! I have never had such delectable, melt-in-your-mouth steak! Our guests took the recipe home with them, and we will definitely be using this recipe again!

    Do you think it would work well with pork to make carnitas?

    • says

      Wow, Karen – THANKS for your reply. You just made my day. And, on the pork – I think it will be FABulous. Give it a try!

  4. Jayne says

    Please help! I want to make fajitas for a graduation party… Can the meat hold up on low in a crockpot over so I can have it all done ahead of time and enjoy the celebration? Any ideas? Thanks!

  5. Debbie says

    I am probably overthinking this recipe but I don’t quite understand the recipe/ingredients. I looked up adobo sauce and I’m wondering if I add an additional 2 chiles to my own homemade adobo sauce or is this a recipe for adobo sauce?


  6. says

    I am marinating a top sirloin steak right now that I have already sliced and in a ziploc bag. It smells really good and looking forward to eating it! Thank you! :)

  7. Derek says

    this marinade sounds very good and I will be trying this but I wanted to try my own test but had a quick question
    if using juice in the original marinade how much zest do I use to substitute for juice and if using shrimp how long would you marinate it for with the zest compared to with juice
    thank you for your help

    • says

      Hi Derek – With zest, you can marinate meats longer as you choose, because there is no acid to affect the texture of the meat. So, really it depends on how much of the citrus flavor you want the meat to take on – the longer the marinating time, the stronger the flavor!

      • Derek says

        thank you for your response I have one more quick question if you can help me with please
        how do you substitute juice for rind is it a 1 to 1 ratio if recipe says 1 cup juice do you use 1 cup of zest?
        thank you again

  8. Yvonne says

    Update: I’ve played around with this a little….a T of tomato paste, and t of brown sugar, plus add the juice of the denuded lime :) I usually make one flank steak or two chicken breasts, and now keep about 1/4 of the marinade to toss the veggies in. I usually marinade for 8 or so hours as i rarely have it together enough to prepare the night before. The grilled version (charcoal) is tastiest to me, but I stand by the one skillet method to get the fond from the meat into the veggies in winter.
    Tip: freeze leftover chipotle peppers 2 to a bag, with the sauce divvied up between the bags. It’s enough for most recipes. I rarely use a whole can for anything.
    Thanks again for this recipe. Grilling it outside invariably results in a neighbor over for dinner :)

    • Vera says

      I have this marinading right now (overnight) and I did take your recommendation and I added tomato paste and brown sugar. I think the addition of brown sugar helps to make a nice “crust” on the steak when it is cooked. When I have leftover chipotle peppers, I freeze them in ice cube trays: 1 or two peppers with a bit of sauce per “cube”


  1. […] {Chicken Breast Fajitas} Follow this recipe (so easy) for either chicken or steak. We chose chicken (have you seen beef prices?). Throw it into a gallon bag to marinate and just freeze it that way. Cut up your peppers ahead of time and freeze as is or buy for this meal when you are ready. Thaw, discard marinade, grill, cut to fajita size, devour. Mmmmmmm. Good. (Should have used that one for the corn chowder, oh well). […]

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