Fajita chicken, onions, and peppers baked in a creamy cheese sauce? This Chicken Fajita Casserole may be my favorite casserole yet. It is perfect with a dollop of sour cream and avocado on top and paired with a fresh green salad.
I love Mexican food. It is generally my birthday dinner request. My favorite Mexican restaurant is Jose Tejas in Woodbridge, NJ. There is always a line out the door so you know the food is good. And the margaritas are even better.
But it can be difficult to get out to restaurants with our five kids and difficult to find a babysitter to get out without them. And I admit I crave fajitas more than once a year. Since most of my kids love Mexican food too we add it into the dinner rotation at least a few times a month.
Most of the time we just do tacos and taco salad but this chicken fajita bake is a welcome step up from a typical Taco Tuesday. Once you try my gluten free keto fajita chicken casserole I guarantee you will want to make it again and again. This easy chicken casserole recipe is also low carb, grain-free, sugar-free, and Trim Healthy Mama friendly.
It's quick enough that even if you need dinner tonight and it's 5pm you can make it!
Chicken Thighs - I prefer using boneless chicken thighs in this recipe but chicken breasts work too.
Onions - Any variety of onions are fine.
Peppers - Sweet bell peppers are the best choice for fajitas.
Cream Cheese - Adding cream cheese makes a delicious creamy sauce. It's definitely not traditional but it is SO good. Trust me on this.
Fajita Seasoning - It is so easy to make your own! Click to learn to make my homemade fajita seasoning: Keto Fajita Seasoning. It uses cumin, paprika, garlic powder, onion powder, chili powder, etc.
Shredded Cheese - Shredded cheddar cheese, Monterey Jack, or a Mexican blend are all good choices. For a spicier version try adding Pepper Jack cheese.
That's it! Just 6 ingredients to a delicious dinner!
How to Make a Chicken Fajita Casserole
This does have a few steps but most of the time it is hands-off. With just 6 ingredients you can make a fabulous casserole the whole family will love.
You will only be actively cooking, chopping, and mixing for about 20 minutes.
Step One: Pop the chicken into the oven to bake in the baking dish or casserole dish you will use for the casserole.
Step Two: While the chicken is baking saute the veggies.
Expert Tip: Cooking the vegetables in a skillet helps give this casserole a true fajita flavor. Adding raw vegetables and baking does not yield the same result. If you'd like to make this entirely on the oven you can roast the onions and peppers on a baking sheet instead of pan-frying them.
Step Three: Shred the chicken. Then combine the hot shredded chicken with the veggies, cream cheese, and seasonings in a large bowl.
Expert Tip: Boneless skinless chicken thighs shred easily but if you choose to use boneless skinless chicken breasts instead it may be easier to just chop them.
Step Four: Put the fajita chicken mixture in the casserole dish, top with cheese, and bake until bubbly and golden. Serve this chicken fajita bake with a salad or your favorite fajita toppings!
Dairy-Free - Cutting bake on dairy and still want fajitas? Try these Baked Chicken Fajitas instead.
Spicy - Sautee some jalapeno peppers along with the peppers and onions. For milder heat remove the seeds from the jalapenos. Canned green chilies work too.
Chipotle - Add some smokiness with chipotle puree. Simply blend up a can of chipotles in adobo and add a bit to taste to the cooked chicken mix before its added to the casserole pan.
Cast Iron Skillet - Cook the chicken in the pan, remove, cook the peppers and onions, add all of those to a large bowl, add the other ingredients, and mix. Put back into the skillet and bake until hot and bubbly.
Seasoning - To change it up try my Chicken Taco Seasoning instead of fajita seasoning.
What is Fajita Seasoning?
A blend of spices commonly used for fajitas. I make both my own Homemade Taco Seasoning and Keto Fajita Seasoning. They are quick, easy, and CHEAP!
Can I use chicken breasts?
Yes! Just bake the onions and peppers for 10 minutes before adding strips of raw chicken breasts or they can dry out.
What to serve with Chicken Fajita Casserole?
We serve this with taco fixings like sour cream, keto salsa, keto guacamole, some chopped cilantro, and a green salad on the side. If you have low carb tortillas you love you can scoop this into those. You can also serve it like a fajita salad right on a bed of lettuce. Cauliflower rice is a good choice for a taco bowl base on a low carb keto diet.
Sometimes I make rice and black beans and put them on the side for my kids to make fajita bowls. Growing children need a lot of healthy carbs. And having those on the side helps fill out the meal and stick to our grocery budget. My children will also scoop this into regular flour tortilla sometimes.
A couple of other favorites from Joy Filled Eats are Fajita Stuffed Chicken and healthy Chicken Fajita Nachos. Or make some Baked Chicken Fajitas which are shown on lettuce wraps in the photo above.
When I can't get out to a Mexican restaurant for an authentic fajita this easy Chicken Fajita bake fills my craving and I guarantee it will satisfy yours.
Like what you see? Follow me on Facebook! Love this recipe? Leave a comment & 5-star rating right here! Make sure you don’t miss new recipes by getting email updates!
- 10 boneless skinless chicken thighs (about 2 pounds)
- 1 red pepper seeded and sliced into small strips
- 1 large onion peeled and sliced into small strips
- 8 oz cream cheese softened
- 8 oz shredded cheddar
- 1.5 tablespoon fajita seasoning
- salt & pepper (optional)
- Preheat oven to 350. Put the chicken in the casserole dish you will be using for this dish. Cover with foil and bake until cooked to 160 degrees, about 30-35 min. Cool for a few minutes and then shred or chop into bite-sized pieces. Drain any cooking liquid from the casserole dish.
- Meanwhile, in a frying pan coated with cooking spray, cook the pepper and onion over medium-low heat until they are golden and soft. I let mine caramelize the entire time the chicken was in the oven. I just left the heat between low and medium and popped into the kitchen to give them a stir every 5-10 min. Cool until warm.
- In a large bowl mix the cream cheese, half of the shredded cheddar, and the fajita seasoning. Add the chopped chicken and cooked onion and pepper. Put back into the same casserole dish you cooked the chicken in. Sprinkle on the remaining cheese.
- Bake at 350 for 25-30 min until hot and bubbly.
Originally Published April 14, 2016. Revised and Republished February 28, 2023.
Joyce Werner says
Would this work in a slow cooker casserole?
I think so. I would drain the chicken before adding the other ingredients if you are planning to cook the chicken in the crockpot.
Have you tried this with ground beef? I’m looking for recipes with something besides chicken.
I haven't tried this one with ground beef but I'm sure it will work. My keto taco casserole uses ground beef (or ground turkey).
Chad venneau says
My wife bought fajita liquid, would I be able to do the recipe with that instead of the powder?
I've never used that before but I'm sure you could just add it to taste. Since you are making this with cooked chicken it's easy to taste test and adjust the seasoning.
Mary Lou says
I am not one to rate or review recipes. But my husband could not stop eating this last night. We loved it.
This was so good! And very filling. I didn't snack all evening. I did the skillet version with some leftover chicken breasts. Quick, easy and definitely a keeper. Taryn, more main dishes like this please! 😋
Rebecca Mills says
Hi, I am looking forward to cooking this tonight. I was wondering if your nutrition panel is Net or Total Carbs?
The nutrition table shows total carbs and fiber. If fiber is not shown that is because it is 0.
Maha A says
You're a life saver!! I'm new to the keto world, and I really needed some keto recipes. I'll be trying this today. Thank you 😊
Monica Baker says
I made tonight for supper. It is now one of my favorites. So very delicious!!
We make this a lot as a skillet meal. It is one of our favorites!
I dice the chicken and brown in the skillet with the fajita seasoning. Just before it is completely cooked, I add in the peppers and onions and cook until softened. I then stir in the cream cheese until melted. Stir in 1/2 the shredded cheese until melted. I usually add some HWC and /or broth at this point. Once everything is melted and heated through. I top with the remaining cheese. 😋
I doubled the cheese. I used one cup to mix it in with the chicken and one cup to sprinkle on top before it bakes.
Hubby said for me to make it again! We all loved it. Thank you for this great healthy recipe! It's a keeper!
This is one of the first Keto chicken casseroles that I have actually liked! I had about 1-1/2 lbs of leftover rotisserie chicken so I used that. This was so good and not dry like most keto chicken casseroles. I think it’s the cream cheese! I put it in a 8x8 and it was pretty full. This will be 6 servings for us. Thank you for sharing!