Steak fajitas made with sirloin are so flavorful and surprisingly easy to make. You don't have to serve them in tortillas! They're very good by themselves or in lettuce wraps.
I adore Mexican food. The flavors are so bold! If I absolutely had to choose my favorite cuisines, I suspect Mexican and Indian would be right up there competing for the top spot. I love boldly seasoned dishes.
If you too enjoy intense flavors, these fajitas won't disappoint. The spice mix I use is amazing. So wonderfully flavorful! Plus, this is such an easy recipe. It's ready fast, so it's perfect for a weeknight dinner.
The ingredients you'll need
The list of ingredients for making steak fajitas is simple. Yes, you need quite a few spices. But the flavor is well worth it! The exact measurements of the ingredients you'll need are listed in the recipe card below. Here's an overview:
Seasoning mix: Salt and pepper, chili powder, smoked paprika, garlic powder, dried oregano, and red pepper flakes.
Bell peppers: It's fun to use different colors, and it makes the dish so pretty. You can also make life easy - as I do in the video below - by using a package of frozen sliced bell peppers. They do add extra liquid to the dish, but I haven't found that to be an issue.
Onion: Thinly sliced. You can use either yellow onion or white onion.
Top sirloin steak: Sometimes I buy the pre-sliced strips sold in trays at the supermarket. But it's easy to slice it yourself. See the detailed discussion below about what meat to use.
Oil: Since we're engaging in high-heat cooking here, it's a good idea to use an oil with a high smoke point such as avocado oil.
How to make steak fajitas
It's easy! Scroll down to the recipe card for the detailed instructions. Here are the basic steps:
Your first step is to mix the spices together in a small bowl. You can actually do as I do in the video and mix them in two separate bowls. Half will season the veggies and the other half will season the meat.
Cook the vegetables with half the spices until tender, then remove them to a plate.
In the same skillet, cook the beef strips with the remaining spices, then add the vegetables back and cook everything together until heated through.
How do you make the meat tender?
Marinating the steak helps to tenderize it. But if you use top sirloin strips, which are more tender than bottom sirloin, you can actually skip the marinade.
Simply season the beef and the vegetables well, saute them quickly, and the steak fajitas will turn out just as delicious and flavorful as if you've made the dish with marinated beef.
And if you're willing to use beef tenderloin in this recipe, it will turn out even more tender. But it's obviously an expensive cut of beef, and most would feel it's better served as steak.
How to serve steak fajitas?
The classic choice would be flour tortillas. But you can absolutely serve them on a bed of cauliflower rice or shredded lettuce, or use lettuce wraps (Boston lettuce makes excellent wraps).
They are also great served on a plate and eaten with a fork and a knife. And that's how I usually serve them.
You can top them with several tasty toppings such as guacamole, sour cream, salsa, and shredded cheese.
What about leftovers?
If you have any leftovers, they keep well in the fridge for 3-4 days in an airtight container. Gently reheat them the microwave on 50% power prior to serving.
A chicken alternative
Personally, I am partial to beef. But if you'd rather use chicken, check out this easy recipe for super tasty chicken fajitas!
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Steak Fajitas
INGREDIENTS
Seasoning mix:
- 1 teaspoon fine sea salt or 2 teaspoons kosher salt (such as Diamond Crystal)
- ¼ teaspoon black pepper
- 2 tablespoons chili powder
- 1 teaspoon smoked paprika
- 1 teaspoon garlic powder
- ½ teaspoon dried oregano
- ½ teaspoon red pepper flakes
Fajitas:
- 3 large bell peppers cut into thin strips (or 1 lb. frozen sliced bell peppers)
- 1 large onion thinly sliced (8 oz)
- 2 lb. top sirloin steak cut into thin strips
- 2 tablespoons avocado oil
Optional, for thickening the juices:
- 1 tablespoon cornstarch
INSTRUCTIONS
- In a small bowl, mix together the seasoning ingredients. You can mix them in two separate bowls - half will season the veggies and the second half will season the meat.
- Heat the oil in a large, deep skillet over medium-high heat, about 2 minutes. Add the bell peppers, the onions, and half the spices. Cook, stirring often, until just tender, about 5 minutes. Remove the vegetables to a plate.
- Add the steak slices and the remaining spices to the same skillet. Stir-fry just until no longer raw, 3-4 minutes. The beef doesn't need to be fully cooked at this point. It will finish cooking when you add back the vegetables.
- Return the vegetables to the skillet. Stir-fry everything together until heated through, 1-2 more minutes.
- At this point, if you have a lot of liquids in the skillet and you'd like to thicken them, you can reduce the heat to medium and stir in a cornstarch slurry (1 tablespoon cornstarch mixed with 1 ½ tablespoons cold water). Keep cooking until the liquids thicken, about 1 more minute. But this is purely optional.
WATCH THE VIDEO:
NOTES
ADD YOUR OWN NOTES
NUTRITION PER SERVING
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Vered DeLeeuw, LL.M., CNC, has been following a low-carb real-food diet and blogging about it since 2011. She's a Certified Nutrition Coach (NASM-CNC), has taken courses at the Harvard School of Public Health, and has earned a Nutrition and Healthy Living Certificate from Cornell University. Her work has appeared in several major media outlets, including Healthline, HuffPost, Today, Women's Health, Shape, and Country Living. 
