Chicken Fajita Casserole
Fajita chicken, onions, and peppers baked in a creamy cheese sauce? This Chicken Fajita Casserole Recipe may be my favorite casserole yet. It is perfect for busy weeknights with a dollop of sour cream and avocado on top and paired with a fresh green salad.
I love Mexican food. 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 have this freezer friendly taco meat (which I do meal prep), but this chicken fajita bake is a welcome step up from a typical Taco Tuesday. Once you try my low carb keto fajita chicken casserole, I guarantee the juicy chicken and melty cheese will make you want to make it again and again. It’s an easy dinner that is quick enough that even if it’s 5 pm, you can make it!
If you are here because you love Mexican food, make sure to try my Keto Taco Salad Casserole Recipe and Keto Chicken Tortilla Soup.
Ingredients
- Chicken Thighs – I prefer using boneless chicken thighs in this recipe but chicken breasts work too. You can also swap in cooked, shredded rotisserie chicken.
- Yellow Onion – Any variety of onions are fine.
- Red Bell 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. It is mild enough for the whole family.
- Shredded Cheese – Shredded cheddar cheese, Monterey Jack, or a Mexican blend are all good choices. For a spicier version, try adding Pepper Jack cheese.
See quantities in the recipe card.
How to Make a Chicken Fajita Casserole
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.
Top 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 fajita veggies, cream cheese, and seasonings in a large bowl.
Note: 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 easy chicken fajita casserole with a salad or your favorite fajita toppings!
Storage
Store leftovers in an airtight container in the fridge for 4-5 days.
Variations
Dairy-Free – Cutting back on dairy and still want fajitas? Try these Baked Chicken Fajitas instead.
Spicy – Sauté 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.
Common Questions
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 do I serve with a fajita casserole?
I normally have this on top of cauliflower rice with a green salad on the side. My kids like to add white rice or brown rice, black beans, and tortilla chips. You will definitely want to serve it with traditional toppings like pico de gallo or salsa, sour cream, and guacamole.
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Video
Chicken Fajita Casserole
Ingredients
- 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 tbsp fajita seasoning
- salt & pepper (optional)
Instructions
- 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.
Notes
Nutrition
Originally Published April 14, 2016. Revised and Republished October 13, 2025.
Absolutely delicious. This will be made on my food rotation. Thank so much.
This has quickly become a family favorite. My non-keto family like to eat it with tortilla chips, but I think it’s equally good on its own.
I preseasoned the chicken with Sazon and Fajita seasoning. It was amazing
We had this for dinner tonight…and the rest of the week. We really liked it! I made the mistake of telling my husband to pick up 4 bell pepper at the supermarket so I added 3 peppers, red, yellow and green. I thought it would be dry because I had one brick of cream cheese to use but it turned out marvelous! My husband loved it and I’m sure it’ll be in the regular rotation.
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).
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.
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! 😋
Hi, I am looking forward to cooking this tonight. I was wondering if your nutrition panel is Net or Total Carbs?
Thanks
The nutrition table shows total carbs and fiber. If fiber is not shown that is because it is 0.
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 😊