Broiling these sheet pan chicken fajitas instead of baking gives the peppers and chicken a deep char you can't get any other way. One pan gets keto dinner on my table in under 30 minutes, with 4.4g net carbs and 29.6g protein.
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.
Most sheet pan fajitas recipes tell you to bake everything at 400°F. I tried that for years and always got the same result: soft peppers, pale chicken, and zero of that smoky flavor you actually want. When I switched to broiling on high, everything changed. The peppers blister and char, the onions get that sweet caramelized edge, and the chicken picks up real color in minutes.
I keep the ingredient list short on purpose. Chicken thighs, bell peppers, a yellow onion, avocado oil, shredded Colby Jack, and a homemade chili-garlic seasoning blend. The whole thing is done in about 25 minutes, and my family goes through it fast enough that I have started doubling the chicken.
Why I Broil Instead of Bake
I have looked at dozens of other recipes online, and almost all of them call for baking at 375-425°F. Baking works, but it steams the vegetables instead of charring them. Broiling on high heat does two things: it cooks faster (less time for moisture to pool) and it creates real char on the peppers, onions, and chicken. That charred flavor is the entire point for me. If I wanted soft roasted vegetables, I would make a different dinner.
I set the rack on the top position, about 4-6 inches from the heating element. The peppers blister and the chicken gets golden-brown edges in a fraction of the time baking would take. The smell fills the kitchen fast enough that my family starts hovering before the timer goes off.
Chicken Thighs vs. Breasts
I use boneless, skinless chicken thighs for this recipe because they have more fat, more flavor, and more forgiveness under the broiler. If you overcook a thigh by a minute or two, it stays juicy. A breast in the same situation dries out fast. I have tested breasts under the broiler after a reader asked, and they work if you pull them at 5-6 minutes per side instead of running them as long as the thighs.
Skirt steak is another option that chars beautifully. A reader named Susan put me onto this, and I tried it with the same chili-garlic seasoning. I pulled the steak at about 8 minutes and it was perfect. Shrimp works too, but cut the broil time to 5-6 minutes total or they go rubbery. If you want another fast protein dinner, my chicken stir fry has the same quick-heat approach.
Low Carb Tortilla Options
If you want to wrap these up in tortillas, I have tested a few low carb options that hold up. Mission Carb Balance flour tortillas are the closest to real tortillas I have found at a regular grocery store, but they contain gluten. If that is a concern, Egglife wraps (made from eggs) are a solid pick for avoiding both gluten and nuts.
My favorite move lately is cheese taco shells as the base. They get crispy and add another layer of flavor. The charred chicken and peppers against a crunchy cheese shell is something else. You can also go bowl-style over cauliflower rice, pile everything into zucchini taco boats, or try my sheet pan chicken and veggies if you want another one-pan dinner with the same easy cleanup.
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. If you want deeper flavor, you can season and refrigerate for up to 2 hours, but even 10 minutes makes a noticeable difference. Pull the chicken when it hits 165°F on an instant-read thermometer and you are good.
In a small bowl, whisk together chili powder, garlic powder, onion powder, salt and pepper. Set aside.
2
Slice peppers and onions
Slice the red bell pepper, green bell pepper and onion into long thin strips. Remove seeds from the peppers.
3
Char-broil peppers and 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.
4
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.
5
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.
6
Sprinkle cheese
Sprinkle shredded cheddar evenly over the sheet pan fajitas and broil for another 1-2 minutes until cheese has melted. Remove from the oven and squeeze lime juice and chopped cilantro over chicken fajitas. Serve by itself, over cauliflower rice or in a low-carb tortilla.
Nutrition
Per serving: 1/6 of recipe
Calories
355
Fat
25g
Protein
29.6g
Total carbs
6.2g
Net carbs
4.4g
Nutrition is an estimate calculated from the ingredients listed. Brands vary, so check labels if you track closely.
Frequently Asked Questions
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.
The sizzle when I pulled the pan out told me something had worked before I even looked. Pretty new to keto, and this was the first thing that felt like real cooking instead of just swapping ingredients. Those darker caramelized bits on the peppers had this sweet smokiness I wasn’t expecting from a home broiler. My question for next time: I have a gas oven, and broilers vary, so mine might’ve needed another minute. Does it make sense to leave the chicken an extra 90 seconds if the peppers aren’t charred enough? Already building my grocery list for round two.
Hi, I’m going to try making this with chicken breasts. I read the recipe and watch your video and I see that you said this… “I have tested breasts under the broiler after a reader asked, and they work if you pull them at 5-6 minutes per side instead of running them as long as the thighs.” The 5 to 6 minutes per side is confusing to me. I didn’t see where we were supposed to cook it per side for anything else, I just saw total time, and I’m wondering if this is a typo or does this actually mean that I’ll have to pull the sheet pan out and turn the chicken pieces? Also, I don’t have avocado oil but I have extra virgin olive oil and refined coconut oil.. would either of those be better than the other for this recipe? I was thinking I would just use the EVOO.
You and I are on the same page, Riley. That’s why the lime squeeze sits at the very end of the steps, right after the cheese melts. Under the broiler that brightness just cooks off.
Rack position matters way more than I expected. Top third of the oven, not the middle shelf. Peppers started charring in under 4 minutes and the chicken cooked through without going rubbery. First batch was pale and kind of sad, and I blamed the recipe until I moved the rack up. Four stars, but that’s a me problem, not a recipe problem.
Camila, the middle shelf is the most common miss I see with this recipe. Broilers heat from the top, so everything below the top third just bakes, which is exactly what you got that first batch. Glad you ran the experiment.
Nine months keto and somewhere along the way I stopped expecting fajitas to actually taste like fajitas. Never could quite nail it. Made this last Tuesday and something actually landed. The seasoning ratio is simpler than what I’d been doing, which should not work but completely does. 4.4 grams carbs and 29 grams of protein per serving. Didn’t expect that from something this filling. I’ll pull the chicken a minute sooner next time, mine came out slightly overdone, which is why I’m not giving it five stars. But this is the fajita recipe I’d given up on finding.
I kept thinking broiling on a sheet pan was going to give me sad, steamed peppers with zero color on them. Made it anyway because I had chicken thighs to use up, and the char on those peppers and onions was real. When the onion tips go dark and crispy at the edges and the chicken gets that slight crust from the broiler, that’s it. That’s the whole thing. Going in the weeknight rotation.
The char on those broiled peppers is what got me. But it’s the meal prep that keeps me coming back. I double the recipe every Sunday, and by Thursday the chicken is still actually tender, not that rubbery reheated texture I’m used to. Cast iron skillet, medium heat, three minutes and it’s back. Tried two other sheet pan fajita recipes and both were soggy by day two. Chicken thighs are the reason, I’m pretty sure. They stay juicy even on day four. 29.6g protein per serving means lunch is sorted before Monday, and the whole batch takes under 30. Hard to argue with.
Thighs are exactly why. Breasts lose that texture by day two, not enough fat to protect them on the reheat. Hot skillet is the only right call, microwave just ruins it.
Assumed sheet pan meant sacrificing the char you get from a hot skillet, so I almost skipped this. The broiler actually blisters the peppers and the chicken edges get this caramelized thing that my cast iron doesn’t do. Converted.
Threw some sliced mushrooms in with the peppers on a whim and they charred up the same way under the broiler. Soaked up the fajita seasoning and had this almost smoky edge to them. If you’ve got extra mushrooms to use up, worth trying.
My husband has been politely tolerating keto dinners for six months. He watched me pull this off the broiler, looked at that char on the peppers and chicken, and said ‘okay, this one I actually want.’ First time he’s asked for leftovers.
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.
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!
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.
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.
