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.
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 8×8 and it was pretty full. This will be 6 servings for us. Thank you for sharing!
Could not get the spice How do I make it
There is a link within the post. It’s under Fajita Seasoning.
Any idea what serving size is?
1/8th of the casserole. You can just cut it into 8 pieces.
I have not tried this recipe yet, but it looks delicious! I just found your site and since I’m doing low carb, it is perfect. Hope to make some of your other recipes too. Thank you so much for easy to read and follow recipes.
do u put foil on second round when everything in.
I don’t. I like the cheese on top to brown.
Wow! It just came out of the oven and I had to sample it. I just tasted a small bite, family coming for supper, so it wouldn’t look very nice if I’d gouged a big hole in it before time to eat! Pretty tasty if you ask me. In order for the rest of the fam to eat it, I’ll have to use breasts, so I may add chicken broth to keep it from drying out too much.
This is on the dinner rotation now. Thanks for posting this recipe! Yum!
I love this recipe. It is delicious. It does freeze nicely even with the cheese on the top.
What can you sub for cream cheese?
Ricotta cheese or sour cream.
So bake the chicken with no seasoning? And then shred and add seasoning? I am not a great cook, obviously, and may be a dumb question, but thought I’d ask. I am using chicken breasts and don’t want them to be dry.
I’ll season the chicken breasts with a little salt and pepper and bake them covered. Just make sure to check them frequently with a meat thermometer. Take them out when they reach 158 degrees and let them rest to reach 160. They will not be dry if you use this method. They get dry when the temp goes above 160-165.
Soooo good!!! I really just came back to make sure I’d pinned it!! And notes for myself: rotisserie chicken, add 1/2 can chicken broth, 1/2 cup HWC, 2 packs fajita seasoning, cast iron grill peppers and onion with olive oil and 1/2 pack seasoning. Top with sour cream and pico. #CompanyWorthy!!!!!!
What is HWC?
Heavy Whipping Cream
what is HWC?
Heavy whipping cream
Did you use HWC & chicken broth in place of cream cheese or in addition?
What size casserole dish are you using?
Three quart. I normally use a standard 9 x 13 size pyrex.