These Keto Steak Fajitas are made with skirt or flank steak, bell peppers, which is marinated in a delicious sauce.

This is an easy weeknight dinner! Skirt steak gets juicy and tender in a marinade of lime juice and soy sauce, for a meal that can be prepped ahead of time! It’s no wonder, when they are super easy to make and perfect for a quick throw-together meal!
I used low carb tortillas for this recipe to keep it keto, although you do not even need to use tortillas. This meal is totally family friendly – your kids will absolutely love it. I love to top each fajita with guacamole, salsa, and sour cream!
If you love this recipe, feel free to try my Chicken and Shrimp Fajitas or my Pork Birria Tacos.
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Ingredients
You'll only need a few simple ingredients to make this. The exact measurements are listed in the recipe card below. Here's an overview of what you'll need:
- Skirt or Flank steak
- Bell peppers
- Red onion
- Olive oil
- Soy sauce
- Apple cider vinegar
- Jalapeno
- Limes
- Orange
- Garlic
- Cumin
- Onion powder
- Oregano
- Cilantro
See recipe card for Keto Steak Fajitas quantities.
Instructions
Add the olive oil, soy sauce, apple cider vinegar, jalapeño, red onion, lime juice, orange juice, garlic, cumin, onion powder, oregano, cilantro and salt and pepper in a mixing bowl and stir well. Add the skirt steak and mix with your hand. Refrigerate and marinate for 2-4 hours. The longer the better – you can even do overnight!
Heat a large cast iron over medium-high heat for 3 minutes. Once hot, add a bit olive oil. Sauté the onions until soft, about 4 minutes. Add the bell peppers and keep stirring until soft, about 5 minutes. Place the onions and peppers on a separate plate.
Raise to high heat and in the same cast iron, add the steak and press down firmly on the surface. Sear for 2 minutes on each side. Reduce heat and add ½ cup of the marinade and cook for 2-4 minutes longer. You want an internal temperature of 130 F. Work in two to three batches if needed. Transfer the steak to a cutting board and let it rest for 10 minutes before slicing.
Meanwhile warm up the store-bought tortillas or try making my Vegan Flour Tortillas. If you have a gas stovetop, I like to place the tortillas directly on the burner and warm them there so give them a nice char. Slice the steak into ½ inch slices. Assemble the fajitas: Place the steak and vegetables on each tortilla. Top with guacamole, pico, and/or sour cream.
Hint: Skirt steak usually comes in a long strip. Cut the steak into 2-3 pieces to allow them to fit better in the pan.
Substitutions
Steak: I personally love skirt steak more than mosts steaks because they have more fat, which gives the most flavor. Flank steak will work perfectly for this too.
Tortillas: If you would like this recipe to be keto, make sure to use low carb tortillas or no tortillas at all. I like using flour tortillas for fajitas for a nice tex mex touch, although you can use corn tortillas instead. I have seen new corn and flour tortilla combinations as well.
Onion: I used red onion for this recipe, although you could use yellow or white onion as well.
Bell pepper: I chose to use green and red just for an aesthetically pleasing color, but you can choose any variation you want. You could even use poblano peppers.
Variations
Cooking is a chance to be creative! Have fun with it and feel free to make your own variation.
- Spicy - add chili pepper flakes while cooking to imbue heat into the dish, or top with hot sauce at the end.
- Deluxe - add guacamole, crispy onions or sour cream on top.
- Kid friendly - add crushed tortilla chips into the taco for a nice crunch.
Check out this Peruvian Ceviche with Leche de Tigre for an appetizer to have before these Keto Steak Fajitas.
Equipment
Equipment can have a big impact on how a recipe turns out. Stone bakeware takes longer to heat up than metal pans, and also retain heat for longer, which could make the recipe more watery, or burnt on the outsides.
I love using my Caraway pots, pans and baking sheets for best quality. Get yourself a discount by clicking here!
Storage
This will be good in the refrigerator for 2-3 days.
The steak can be frozen for up to three months. The rest of the ingredients don't stand well to freezing.
Top tip
To marinate, alternatively, you can use a large Ziplock bag. Before searing the steak, dry it with paper towel – keep the marinade.
Keto Steak Fajitas
- Total Time: 1 hour 30 minutes
- Yield: 4 servings 1x
Description
These keto steak fajitas are made with skirt or flank steak, bell peppers, LOW CARB tortillas and marinated in a delicious sauce.
Ingredients
- 2 pounds skirt steak or flank steak, thinly sliced across the grain
- 2 bell peppers, red and green, sliced
- ½ red onion, sliced
- optional: 8-10 LOW CARB tortillas
Marinade:
- ¼ cup olive oil
- ¼ cup soy sauce
- 2 tablespoons apple cider vinegar
- 1 jalapeño diced
- ½ red onion
- Juice of 1 lime
- Juice of 1 orange
- 1 tablespoons minced garlic
- 1 teaspoon ground cumin
- 1 teaspoon onion powder
- 1 teaspoon oregano
- ½ bunch cilantro
- 1 teaspoon pepper
- 1 teaspoon salt
Toppings:
- Sour cream
- Guacamole
- Pico de gallo
Instructions
- Skirt steak usually comes in a long strip. Cut the steak into 2-3 pieces to allow them to fit better in the pan.
- Add the olive oil, soy sauce, apple cider vinegar, jalapeno, red onion, lime juice, orange juice, garlic, cumin, onion powder, oregano, cilantro and salt and pepper in a mixing bowl and stir well. Add the skirt steak and mix with your hand. Refrigerate and marinate for 2-4 hours. The longer the better – you can even do overnight! Alternatively, you can use a large Ziplock bag.
- Before searing the steak, dry it with paper towel – keep the marinade.
- Heat a large cast iron over medium-high heat for 3 minutes. Once hot, add a bit olive oil. Sauté the onions until soft, about 4 minutes. Add the bell peppers and keep stirring until soft, about 5 minutes. Place the onions and peppers on a separate plate.
- Raise to high heat and in the same cast iron, add the steak and press down firmly on the surface. Sear for 2 minutes on each side. Reduce heat and add ½ cup of the marinade and cook for 2-4 minutes longer. You want an internal temperature of 130 F. Work in two to three batches if needed.
- Transfer the steak to a cutting board and let it rest for 10 minutes before slicing.
- Meanwhile warm up the tortillas. If you have a gas stovetop, I like to place the tortillas directly on the burner and warm them there so give them a nice char.
- Slice the steak into ½ inch slices.
- Assemble the fajitas: Place the steak and vegetables on each tortilla. Top with guacamole, pico, and/or sour cream.
Notes
- Marinate the steak overnight for maximum flavor.
- Feel free to top with sour cream, guacamole and/or pico de gallo. Get as creative as you want.
- Make sure the temperature is very high when cooking the steak, and LET IT REST. The steak continues to cook as it rests.
- Prep Time: 1 hour
- Cook Time: 30 minutes
- Category: Dinner
- Method: Cooking
- Cuisine: Tex Mex
Nutrition
- Serving Size: 1
- Calories: 431.7
- Sugar: 1.9 g
- Sodium: 893.8 mg
- Fat: 15.7 g
- Saturated Fat: 4.5 g
- Carbohydrates: 38.8 g
- Fiber: 3.7 g
- Protein: 33.4 g
- Cholesterol: 77.6 mg
Food safety
- Cook to a minimum temperature of 165 °F (74 °C)
- Do not use the same utensils on cooked food, that previously touched raw meat
- Wash hands after touching raw meat
- Don't leave food sitting out at room temperature for extended periods
- Never leave cooking food unattended
- Use oils with high smoking point to avoid harmful compounds
- Always have good ventilation when using a gas stove
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