Low-Carb Grilled Chicken Fajitas

Here are my grilled chicken fajitas, with marinated chicken strips in lime juice and fajita seasoning, colorful bell peppers and onions charred on the grill, and warm tortillas ready to be loaded up with all your favorite toppings.

These fajitas are a weeknight staple at our house because they come together so quickly and everyone gets to build their own. Plus, cooking everything on the grill means less cleanup, which is always a win in my book!

What Kind of Chicken Should I Use?

Boneless, skinless chicken breasts are the classic choice for fajitas, and they’re what I recommend for this recipe. If your chicken breasts are on the thicker side (more than ½-inch), you’ll want to pound them out or slice them horizontally so they cook evenly on the grill. Chicken thighs are another great option if you prefer darker meat – they’re a bit more forgiving since they won’t dry out as easily, plus they have extra flavor. Just make sure whatever you choose is relatively uniform in thickness so everything finishes cooking at the same time.

Options for Substitutions

This fajita recipe is easy to customize based on what you have in your kitchen:

• Chicken breasts: Chicken thighs work great here and actually stay juicier on the grill. You can also use flank steak or shrimp if you want to switch up the protein entirely.
• Fajita seasoning: If you don’t have fajita seasoning, make your own with 1 tablespoon chili powder, 1 teaspoon each of cumin and paprika, ½ teaspoon garlic powder, and a pinch of cayenne.
• Limes: Out of limes? Lemon juice works in a pinch, though it gives a slightly different flavor. You could also use 1 tablespoon of white vinegar mixed with 1 tablespoon water.
• Bell peppers: Use whatever color peppers you have on hand – all one color is totally fine. You can also add poblano peppers for a mild smoky kick.
• Flour tortillas: Corn tortillas, whole wheat tortillas, or even lettuce wraps work well if you’re looking for different options. Just warm them up before serving.
• Olive oil: Any neutral cooking oil like vegetable, canola, or avocado oil will do the job just fine.

Watch Out for These Mistakes While Grilling

The biggest mistake with grilled chicken fajitas is overcooking the chicken, which turns it dry and chewy – pull it off the grill when it hits 160°F since it’ll continue cooking while it rests and reach that safe 165°F temperature.

Don’t make the error of cutting your peppers and onions too thin, as they’ll fall through the grill grates or burn before the chicken is done – keep them in larger chunks or quarters so they cook evenly alongside the meat.

Another common issue is not oiling your grill grates properly, which causes the chicken and vegetables to stick and tear when you try to flip them, so make sure to brush or spray oil on the grates right before adding your food.

Finally, resist the urge to slice into that chicken right away – letting it rest for those full 5 minutes allows the juices to redistribute, giving you tender, moist meat instead of a dry disappointment.

What to Serve With Grilled Chicken Fajitas?

I love serving chicken fajitas with all the classic toppings like sour cream, guacamole, shredded cheese, and fresh pico de gallo so everyone can build their perfect fajita. A side of Mexican rice or cilantro lime rice is always a hit, and it helps make the meal more filling. Refried beans or black beans work great too, especially if you warm them up with a little cheese on top. For something lighter, a simple corn salad or chips with salsa on the side rounds out the meal nicely.

Storage Instructions

Store: Keep your leftover chicken and veggies in separate airtight containers in the fridge for up to 4 days. I like to store them separately so the chicken doesn’t get soggy from the veggie juices. When you’re ready to eat, just warm everything up and assemble fresh tortillas for a quick weeknight dinner.

Freeze: The grilled chicken and peppers freeze really well for up to 3 months. Let everything cool completely, then pack them in freezer bags with as much air squeezed out as possible. I wouldn’t freeze the tortillas with the filling though – they get kind of weird and mushy.

Reheat: Warm up your chicken and veggies in a skillet over medium heat for about 5 minutes, stirring occasionally until heated through. You can also microwave them, but I find the skillet method keeps everything from getting rubbery. The tortillas are best warmed fresh on the stove or in the microwave for just a few seconds.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1300-1500
• Protein: 80-95 g
• Fat: 38-48 g
• Carbohydrates: 140-170 g

Ingredients

For the marinade:

• 3 tbsp olive oil (Bertolli Extra Virgin)
• 2 limes, freshly squeezed
• 2 1/2 tbsp McCormick fajita seasoning
• 2 cloves garlic, minced

For the grill:

• 1.25 lbs chicken breasts (cut into 1/2-inch thick strips)
• 2 red bell peppers (seeded and halved for grilling)
• 1 yellow bell pepper
• 1 green bell pepper
• 1 large white onion (sliced into 1/2-inch thick rounds)

For serving:

• 10 flour or corn tortillas
• 1/4 cup fresh cilantro, chopped

Step 1: Prepare the Marinade and Marinate Chicken

• 3 tbsp olive oil
• 2 limes, freshly squeezed
• 2 1/2 tbsp McCormick fajita seasoning
• 2 cloves garlic, minced
• 1.25 lbs chicken breasts, cut into 1/2-inch thick strips

In a bowl, whisk together the olive oil, freshly squeezed lime juice, fajita seasoning, and minced garlic until well combined.

Place the chicken breast strips into a zip-top bag or shallow container and pour the marinade over them, making sure all pieces are evenly coated.

Seal the bag and refrigerate for at least 20 minutes—I prefer 45 minutes to an hour for deeper flavor penetration, but even 20 minutes makes a noticeable difference.

While the chicken marinates, you can prep your vegetables.

Step 2: Prepare Vegetables for Grilling

• 2 red bell peppers, seeded and halved
• 1 yellow bell pepper, seeded and halved
• 1 green bell pepper, seeded and halved
• 1 large white onion, sliced into 1/2-inch rounds
• 1/4 cup fresh cilantro, chopped

While the chicken marinates, prepare all your vegetables.

Seed the bell peppers and cut them in half lengthwise for easy grilling—keeping them in large, flat pieces prevents them from falling through the grate.

Slice the white onion into 1/2-inch thick rounds, leaving the root end intact so the layers stay together during cooking.

Roughly chop the fresh cilantro and set aside for garnish.

Having everything prepped before you heat the grill keeps the cooking process smooth and prevents any burned items while you’re still cutting.

Step 3: Heat Grill and Set Up Cooking Zone

Preheat your grill to medium-high heat (around 400-425°F if using a gas grill).

Once hot, oil the grate generously using an oil-soaked paper towel held with tongs to prevent sticking.

Let the grill stabilize for a few minutes so the chicken and vegetables develop a nice char.

Having the grill properly heated and oiled is essential for creating those signature caramelized grill marks that make fajitas so appealing.

Step 4: Grill Chicken and Vegetables

• marinated chicken from Step 1
• prepared bell peppers from Step 2
• prepared onion rounds from Step 2

Remove the marinated chicken from the refrigerator and arrange it on the grill along with the pepper halves (skin-side down first) and onion rounds in a single layer.

Grill for 6-7 minutes without moving, allowing the chicken and vegetables to develop a golden char.

Flip everything and continue cooking for another 8-12 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are tender and lightly charred.

I like to use tongs to occasionally rotate the vegetables for even browning rather than constantly flipping them.

Step 5: Rest Protein and Heat Tortillas

• cooked chicken and vegetables from Step 4
• 10 flour or corn tortillas

Transfer the grilled chicken and vegetables to a warm plate and let them rest for 5 minutes—this allows the juices to redistribute, keeping the chicken moist.

While resting, place the tortillas directly on the grill grates for about 1 minute per side, just until they’re warmed through and slightly charred.

Stack them in a clean kitchen towel to keep them warm and pliable for serving.

Step 6: Slice and Assemble Fajitas

• rested chicken and vegetables from Step 5
• warm tortillas from Step 5
• cilantro from Step 2

Slice the rested chicken and grilled vegetables into thin strips for easy serving.

Arrange the warm tortillas on a platter alongside the sliced chicken and vegetables, allowing guests to build their own fajitas.

Garnish with the chopped cilantro and serve immediately while everything is still warm.

Low-Carb Grilled Chicken Fajitas

Delicious Low-Carb Grilled Chicken Fajitas recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 52 minutes mins

Servings: 4 servings

Calories: 1400

Ingredients Method

Ingredients

  

For the marinade

• 3 tbsp olive oil (Bertolli Extra Virgin)
• 2 limes, freshly squeezed
• 2 1/2 tbsp McCormick fajita seasoning
• 2 cloves garlic, minced

For the grill

• 1.25 lbs chicken breasts (cut into 1/2-inch thick strips)
• 2 red bell peppers (seeded and halved for grilling)
• 1 yellow bell pepper
• 1 green bell pepper
• 1 large white onion (sliced into 1/2-inch thick rounds)

For serving

• 10 flour or corn tortillas
• 1/4 cup fresh cilantro, chopped

Method

 

1. In a bowl, whisk together the olive oil, freshly squeezed lime juice, fajita seasoning, and minced garlic until well combined. Place the chicken breast strips into a zip-top bag or shallow container and pour the marinade over them, making sure all pieces are evenly coated. Seal the bag and refrigerate for at least 20 minutes—I prefer 45 minutes to an hour for deeper flavor penetration, but even 20 minutes makes a noticeable difference. While the chicken marinates, you can prep your vegetables.
2. While the chicken marinates, prepare all your vegetables. Seed the bell peppers and cut them in half lengthwise for easy grilling—keeping them in large, flat pieces prevents them from falling through the grate. Slice the white onion into 1/2-inch thick rounds, leaving the root end intact so the layers stay together during cooking. Roughly chop the fresh cilantro and set aside for garnish. Having everything prepped before you heat the grill keeps the cooking process smooth and prevents any burned items while you're still cutting.
3. Preheat your grill to medium-high heat (around 400-425°F if using a gas grill). Once hot, oil the grate generously using an oil-soaked paper towel held with tongs to prevent sticking. Let the grill stabilize for a few minutes so the chicken and vegetables develop a nice char. Having the grill properly heated and oiled is essential for creating those signature caramelized grill marks that make fajitas so appealing.
4. Remove the marinated chicken from the refrigerator and arrange it on the grill along with the pepper halves (skin-side down first) and onion rounds in a single layer. Grill for 6-7 minutes without moving, allowing the chicken and vegetables to develop a golden char. Flip everything and continue cooking for another 8-12 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are tender and lightly charred. I like to use tongs to occasionally rotate the vegetables for even browning rather than constantly flipping them.
5. Transfer the grilled chicken and vegetables to a warm plate and let them rest for 5 minutes—this allows the juices to redistribute, keeping the chicken moist. While resting, place the tortillas directly on the grill grates for about 1 minute per side, just until they're warmed through and slightly charred. Stack them in a clean kitchen towel to keep them warm and pliable for serving.
6. Slice the rested chicken and grilled vegetables into thin strips for easy serving. Arrange the warm tortillas on a platter alongside the sliced chicken and vegetables, allowing guests to build their own fajitas. Garnish with the chopped cilantro and serve immediately while everything is still warm.