If you're craving bold fajita flavors with the ease of a single baked dish, this chicken fajita casserole is your new go-to! Made with just 8 ingredients—including juicy chicken, bell peppers, onions, fajita seasoning, sour cream, and two cheeses—this high-protein, low-carb casserole is cheesy, creamy, and packed with flavor.
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The backstory.
I did it again. I forgot the tortillas.
I swear, every time I make anything remotely enchilada, taco, or fajita-related, I get all excited about the sizzling chicken, the melty cheese, the creamy goodness… and then, as I’m about to start making dinner, it hits me—I forgot the tortillas. Again.
I know you've heard this story before, at this point, it’s practically tradition. But honestly? This chicken fajita casserole is so ridiculously good that nobody even misses them.
xoxo Kori
One reader says:
This chicken fajita casserole recipe is easy and so delicious!! My whole family loved it. Thanks! 😍 - Shannon, Pinterest
The must-make chicken fajita casserole recipe!
Classic fajita flavor - but it's a casserole. This chicken casserole recipe brings the sizzling flavors of a classic fajita into a cheesy, baked dish. No tortillas required (but you can totally add them if you want!).
Quick and easy (one-pan meal)! From stovetop to oven, this fajita chicken casserole comes together in just one skillet (with only 8 ingredients)—which means fewer dishes for you!
It's a healthy chicken fajita casserole! This casserole is high in protein, gluten free (if you use my fajita seasoning recipe), low carb, keto-friendly, and has no added sugar.
- To lower the fat content: use chicken breasts instead of thighs, lowering the quantity of cheese used, and substituting a lower-fat cream cheese and sour cream.
What you'll need.
Here are the ingredients you will need to make this easy chicken fajita casserole:
- Olive Oil
- Chicken Thighs - boneless skinless thighs, but you can also use chicken breast too!
- Bell Peppers - use any favorite color. I love using different colors.
- Yellow Onion - While I used a yellow onion, you could also use a sweet, white, or red onion.
- Homemade Fajita Seasoning Recipe or Copycat Taco Seasoning Mix Recipe - you can use either fajita seasoning mix or taco seasoning. I highly recommend you make your own seasoning mix - it's easy, inexpensive, and much healthier than store-bought.
- Sour Cream
- Cream Cheese
- Shredded Cheddar Cheese - use mild or sharp shredded cheese - whichever you prefer. Substitute pepper jack cheese if you it spicy!
- Optional for Serving: avocado slices, shredded cheese, guacamole, fresh cilantro, or salsa. Don't forget hot sauce for the spicy lovers! 🙂
For exact ingredient quantities, please see the recipe card below!
Make it yours.
- Make it lighter: Swap boneless chicken thighs for boneless chicken breasts to reduce fat, or use Greek yogurt instead of sour cream for extra protein.
- Either taco seasoning or fajita seasoning can be used - use what you have on hand.
- Make this steak fajitas by using sliced sirloin steak, or a shrimp version by using large shrimp (tails removed).
- Cheese swaps: Love spice? Use pepper jack instead of cheddar. Want it extra gooey? Try Monterey Jack or a Mexican cheese blend.
- Dairy-free option: Use a plant-based sour cream and dairy-free cheese to make this lactose-free.
- Spice it up: Add diced jalapeños or a pinch of cayenne for extra heat.
How to make chicken fajita casserole.
You will be pleasantly surprised at how easy this chicken casserole recipe is to make! Here is an overview, for complete details, please see the printable recipe card below. Enjoy!
Cook the chicken
In an ovenproof skillet saute chicken until done. Remove from pan and keep warm
Cook the veg
Saute onions and peppers until tender.
Mix
Add chicken back to the pan. Stir in cheddar cheese, sour cream, and seasoning.
Sprinkle and bake
Sprinkle the top with the shredded cheddar cheese and bake in the oven until cheese is melted.
How do you cut chicken breast for chicken fajitas?
- The most common way is to cut the chicken breast into thin ½" strips sliced horizontally, cutting against the grain.
- Keep in mind that the smaller the pieces, the quicker they will cook so you may need to shorten your cooking time as recommended by the recipe instructions.
How to serve fajita chicken casserole.
Need ideas on how to serve this chicken fajitas casserole? Here are some tasty options:
- My favorite toppings for this dish is salsa and sour cream.
- Serve as-is for a low-carb, keto-friendly meal.
- Not low carb or keto? No problem! This chicken casserole recipe can be served with tortillas, rice, or beans for a meal the whole family will enjoy.
- Spoon over cauliflower rice for a light, grain-free option.
- Wrap in low-carb tortillas or classic flour/corn tortillas for a more traditional fajita-style meal.
- Add a fresh side salad with cilantro lime avocado dressing for a refreshing contrast.
Toppings to Try: Extra shredded cheese, salsa, chipotle crema, roasted chili corn salsa, or hot sauce for a spicy kick!
Love a good fajita? Be sure to try this Chicken Fajita Soup that can be made in your Instant Pot, crockpot, or on the stove. I also have this Instant Pot Chicken Fajitas recipe with delicious Mexican-style rice. Enjoy!
Kori's tips.
- Don’t overbake—Since most of the recipe is cooked, you only need to bake the casserole to get the cheese bubbly and heat the inside. No more, no less. Technically, you don't even have to bake this casserole, but you won't have that nice ooey gooey melted cheese on top!
- Cut chicken into uniform pieces for even cooking.(approx 1" to 2" in size, or you can do 1½" strips if you prefer)
- Cook the onions and peppers to your desired tenderness. Some people love them crisp-tender; others love them completely soft.
- Cook the chicken to 165º - the safe internal cooking temperature.
- If you don't have an oven-proof skillet, just cook chicken, peppers, and onion according to the recipe. Stir in the dairy. Put the mixture into a casserole dish, then top with shredded cheddar cheese and bake.
FAQs
The USDA recommends that chicken should be cooked to 165º degrees. I always check the temperature of my chicken with an instant read thermometer. Here is a link to their Safe Minimum Internal Temperature Chart.
Chicken fajitas are very healthy! With plenty of nutrients, healthy fat, protein, and fiber you will feel satisfied long after your meal is over.
Amazingly, each serving of this chicken fajita bake (keto low carb) has over 100% of your day's vitamin C, 35% Vitamin A, 30% zinc, 23% calcium, and is loaded with Vitamin B's! 48% Vitamin B12, 45% Vitamin B6, 44% Vitamin B3, 41% Riboflavin B2.
Where are all these vitamins coming from? Well, the fats are coming from the chicken, olive oil, cheese, and sour cream. The calcium is mostly coming from the cheese and sour cream, but the bulk of the remaining B's, Vitamin A , and Zinc, are coming from the peppers.
Here's a super interesting article about peppers from WebMD:
Pepper Power: Nutrition and Other Benefits
Fajitas without tortillas and contains approximately 10 grams of carbs per 1 cup serving.
Store any leftover fajita casserole in an airtight container up to 3 days. This recipe does not freeze well as the peppers become very watery and the dairy often separates.
Sorry, you cannot freeze this casserole as the peppers will turn watery and the fats in the dairy will separate.
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📖 The recipe.
Chicken Fajitas Casserole (easy and cheesy!)
Ingredients
- 1 tablespoon olive oil
- 6 (4 to 6 ounces each) boneless skinless chicken thighs or breasts (cut into bite-sized pieces)
- 4 bell peppers (sliced; vary the colors to make it pretty!)
- 1 small onion (sliced)
- 1 recipe or package fajita seasoning mix (taco seasoning may also be used)
- 1 cup sour cream
- 4 ounces cream cheese softened
- 2 cups cheddar cheese grated
- optional for serving: avocado, guacamole, sour cream, and salsa.
Instructions
- Preheat oven to 350 degrees F. Over medium heat, saute the chicken in olive oil until chicken is done. Remove from skillet and set aside.
- Add onions and peppers and saute until desired tenderness is reached.
- Add chicken back to pan and stir in fajita seasoning, sour cream, and cream cheese. Mix well.
- Sprinkle with cheese and bake in oven for 10 to 15 minutes or until cheese is melted.
Video
Kori's Tips
Nutrition
© 2025 Seeking Good Eats™
Keep the good eats going.
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- Green Enchiladas Chicken Soup (Keto Slow Cooker Mexican Soup) - the #1 soup on the website! 🙂
Cavy
This dish is out of this world. It is quick and easy to prepare. It is on my “Fix once a month” menu.
Lynne
My family loved this recipe! It worked for those doing Keto and those who are not. This will be in our regular meal rotation from now on.
Kori Butler
Awwww! Thank you! So glad you love this casserole - it's one of my favorites!
Julie
Great recipe! The only thing I did differently was used just a frying pan and combined everything in it. It was a big hit, thank you so much.
seekinggoodeats
Great! So glad you loved the casserole. Thanks for giving it a try! 🙂
Sasha
Thought i should leave a review incase anybody else has a bell pepper hater in their family. I’ve been eyeing this recipe up but my partner hates bell peppers (very sad i know) so instead of bell peppers i did a can of corn and a can of black beans. So yummy. Second night we baked it on top of nachos! Delish! Thanks for a great recipe!