Sheet Pan Fajitas
Published October 30, 2021 • Updated March 14, 2026
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I broil these chicken fajitas on a single pan instead of baking, and the char on the peppers and chicken is something you cannot get any other way. Keto dinner in under 30 minutes, 4.4g net carbs per serving.
I stopped baking fajitas years ago. Every recipe I tried came out steamed, soft, and missing that smoky char you want from a real Mexican kitchen. So I switched to broiling, and the difference was obvious from the first batch. The peppers blister and get almost jammy around the edges, the onions caramelize instead of just going limp, and the chicken picks up real color instead of sitting in its own steam.
The method here is simple. I season everything with a chili-garlic blend (chili powder, garlic powder, onion powder, salt, pepper), toss the peppers and onions on a foil-lined baking tray first, then add the chicken after the vegetables have a head start. Everything cooks under the broiler on high, and the whole process takes under 30 minutes. No flipping, no babysitting.
I use boneless, skinless chicken thighs because they have more fat than breasts and hold up better under intense heat. Thighs stay juicy even if you run them a minute or two longer, which is forgiving when you are managing a hot broiler.
For serving, I go a few different ways depending on the night. Straight off the pan with lime and cilantro squeezed over the top is my go-to. Over cauliflower rice is excellent if you want more of a bowl. My family also likes these wrapped in tortillas or piled onto a taco salad. If you are feeding a crowd, set out salsa chicken or cilantro lime chicken as a second protein. It turns into a full Mexican night without much extra work. For a casserole version with the same spice profile, try my keto taco casserole.
One reader, Kim, told me her husband stopped in the doorway while these were broiling and asked if she had ordered delivery. He cleared his whole plate without saying a word, which she said is the real signal in their house. That tracks with what I hear from people who make this. The smell alone pulls everyone into the kitchen.
What I like about this dinner is how little cleanup there is. One bowl for the seasoning, one baking tray for everything else. I line the pan with foil, so after dinner I just ball it up and toss it. Twenty-five minutes of active cooking and almost zero dishes. That is why this ends up in our weekly rotation.
How to Make Broiled Chicken Fajitas
The key to getting this right is broiler positioning and pan spacing. I set my oven rack to the top position, about 4-6 inches from the heating element, and spread everything in a single layer. If you crowd the pan, steam gets trapped underneath and you lose the char. That is the number one mistake I see people make with this recipe. I also let the seasoned chicken sit at room temperature for about 10 minutes before it goes under the broiler. That short rest lets the spices absorb into the surface and the chicken cooks more evenly since it is not fridge-cold. Pull the chicken when it hits 165°F on an instant-read thermometer and you are good.
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Ingredients
1 tablespoon chili powder -
1 teaspoon garlic powder
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1 teaspoon onion powder
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1 teaspoon salt
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1 teaspoon black pepper
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1 red bell pepper
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1 green bell pepper
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1 yellow onion
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1/4 cup avocado oil, divided
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2 lb skinless, boneless chicken thighs
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1 cup shredded Colby Jack cheese
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juice from 1/2 lime, optional
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chopped cilantro, optional
Step by Step Instructions
Step by Step Instructions
Mix fajita seasoning
In a small bowl, whisk together chili powder, garlic powder, onion powder, salt and pepper. Set aside.
Slice peppers & onions
Slice the red bell pepper, green bell pepper and onion into long thin strips. Remove seeds from the peppers.
Char-broil peppers & onions
Place sliced pepper and onions on a foil lined rimmed baking tray. Drizzle with 2 tablespoons avocado oil and sprinkle half of the fajita seasoning evenly on top of the bell peppers and sliced onion. Place sheet pan on the top rack and broil on high for 10 minutes or until the onions and peppers start to char. Remove from the oven.
Season chicken
Meanwhile, cut chicken thighs into bite sized strips. Add to a medium bowl and add remaining avocado oil and fajita seasoning. Mix until chicken is evenly coated.
Cook chicken
Evenly spread chicken on top of peppers and onions on the baking tray. Return to oven and broil on high for another 5-10 minutes until chicken is cooked through.
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
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Get My Macros + Recipes →Frequently Asked Questions
Can I use chicken breasts instead of thighs?
I have tested both under the broiler. Breasts work, but they dry out faster because they have less fat. Pull them at 5-6 minutes per side instead of letting them run as long as thighs. The char still comes through (that is from the broiler heat itself, not the cut of meat), but thighs are more forgiving if your timing is not exact.
Why do you broil instead of bake?
I tried baking fajitas for years and always ended up with soft, steamed vegetables and pale chicken. Broiling on high does two things: it cooks faster (less time for moisture to pool on the pan) and it creates actual char on the peppers and meat. That charred flavor is the whole point for me. Once I switched, I never went back.
Can I make these with steak instead of chicken?
I have tried skirt steak with the same chili-garlic seasoning and it chars beautifully under the broiler. I pull it at about 8 minutes (it cooks faster than thighs). A reader named Susan makes this with skirt steak regularly and says it has been in her dinner rotation ever since.
What temperature should the chicken reach before it is safe to eat?
I pull mine when it hits 165°F on an instant-read thermometer. I always check the thickest piece on the pan. The broiler cooks from the top, so the surface can look done while the center still needs another minute or two. An instant-read thermometer takes the guesswork out completely.
Can I make these ahead of time and reheat them?
I have made these on Sunday and reheated portions through the week. Store everything in an airtight container in the fridge for up to 3-4 days. The key to reheating is a hot skillet, not the microwave. A skillet revives the char and crisps the edges back up. The microwave just steams everything and you lose the texture that makes this recipe worth making.
What if my broiler does not work? Can I bake these instead?
I have had readers ask me this before. Bake at 400°F for about 15-20 minutes until the chicken is cooked through. You will get a good meal, but you will not get the same char. If you have a grill or a cast iron pan, you can sear everything after baking to get closer to that broiled finish.
Can I make this with shrimp?
I have tried shrimp with the same seasoning and it works well. The only change is timing. Cut the broil time to 5-6 minutes total or the shrimp go rubbery. Same seasoning, same pan setup, just watch them closely because they turn fast under the broiler.
Do I need to marinate the chicken first?
I do not do a long marinade, but I let the seasoned chicken sit at room temperature for about 10 minutes before it goes under the broiler. That short rest lets the spices absorb into the surface and the chicken cooks more evenly since it is not fridge-cold. If you want deeper flavor, you can season and refrigerate for up to 2 hours, but even 10 minutes makes a noticeable difference.
Made these on a Tuesday because I had chicken thighs to use up, threw everything on the pan and didn't really expect much. My husband came in from the garage while it was still in the oven and literally stopped in the doorway, asked if I had somehow gotten delivery (we're nowhere near a place that makes food this good). That char from the broiler is no joke and the smell coming out of the oven is unreal. He cleared his whole plate without saying a word, which in our house is the actual signal, not the polite 'that was good honey.' I made cauliflower rice bowls for us and threw some tortillas on the side for the kids and everyone just ate. Doubling the chicken next time, probably adding extra peppers too because they caramelize so well in there.
That 'cleared his plate without a word' is so much better than 'that was good honey.' Extra peppers get almost jammy under the broiler, add as many as will fit.
I only have chicken breasts in my freezer, not thighs. Will they dry out under the broiler, or does the avocado oil coating help enough? I really want that char-broiled look from your photos so I don't want to mess it up.
Breasts will dry out faster, and the avocado oil coating helps but doesn't save you if you run them as long as thighs. Pull them at 5-6 minutes per side instead. The char comes from the broiler heat itself, not the cut.
So I just had to leave a review on this recipe. Oh my goodness! YUM!! This sheet pan fajita recipe was so easy and so delicious! I will definitely be making this on a regular basis! It was a BIG hit with my non keto family members as well! Have you ever made it with shrimp? I might try that next. Thanks for all your delicious recipes!
Love that non-keto folks approved. Shrimp works, just cut the broil to 5-6 minutes or they'll go rubbery. Same seasoning holds up.
We just found and cooked this recipe and it was absolutely delicious. We didn't use lime juice and cilantro, and mozz cheddar mix for the cheese because that's what we had on hand.
Mozz cheddar melts better than Colby Jack anyway. And yeah, lime and cilantro are easy skips on these, they're more of a brightness thing at the end.
This is one of my favorites! I even tried it with skirt steak instead of chicken and it was delicious. This is now in my regular dinner rotation! I love how quick and easy it is to make.
Skirt steak with that chili-garlic blend is a good call. Chars beautifully under the broiler. I'd probably pull it at 8 minutes, it cooks faster than the thighs.
Can You Just Bake This Chicken Fajitias My Broiler Doesn't Work. Going To Make This W All The Veggies???
Yes, bake at 400 degrees for about 15 minutes or until the chicken is cooked through
This is a WINNER -- even my hard-to-please son loved it! The broiling makes all the difference, and it's so quick and easy. It will definitely become a regular on our meal rotation. Thanks for a great recipe!
Ha, hard-to-please sons are the real test. The broil is everything on this one. That char you just can't fake with a regular bake.
So easy and so good! This one caught my eye on Instagram and was a winner for sure. Thanks for such great posts / recipe ideas!!
:) it is my pleasure!
This is an amazing recipe . My family loves it. I make it once a week
Weekly rotation is about right. The broiler char on the peppers is the part I can't fake with any other method.
This keto sheet pan fajitas recipe is a total winner and I will be making this for my family and friends. It's so EASY to make and the flavor is amazing!
So good for a crowd. Squeeze the lime over the pan right when it comes out, before you serve.