Looking for a delicious and easy one-pan dinner that the whole family will love? Look no further than this chicken fajita casserole recipe! Packed with juicy chicken, flavorful peppers and onions, and all the classic flavours you love in a fajita. This casserole is the perfect way to spice up your dinner routine.

Best of all, it's simple to make and can be customized to your liking with your favorite toppings and sides. So why wait? Make your shopping list, grab your ingredients and get ready to savor the flavors of Mexico in every bite!
If you love the flavours of Mexico you might also love my recipe for Green Chicken Chili.
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Why you will love this recipe
- Fast and easy to make - Who doesn't love one pot meals? With just a few simple steps, you can have a hearty and flavorful meal on the table in no time.
- Versatile - This recipe is very versatile, allowing you to customize it to your own liking. You can add additional spices or ingredients, such as black beans or corn, to make it your own.
- Heathy and nutritious - This casserole is full of lean protein and nutritious vegetables.
- Makes the best leftovers! - This casserole can easily be reheated for the most delicious leftovers. That is if you have any left!
If you love one-pan chicken recipes you might like this recipe for Mediterranean Chicken Thighs for a different flavour palette.
Ingredients and Substitutions
Please refer to the recipe card below for a full list of ingredients and quantities.

Bell Peppers - Multicoloured peppers are more visually appealing but you can use only one or 2 if you prefer.
Chicken breast - Sliced chicken thighs also work perfectly in this recipe. You can also use sliced beef or pork.
Green and white onion - Green onions make a nice, fresh garnish and white onions add some sweetness to the casserole. A great substitute for the green onion garnish would be finely diced red onion and any type of onion can be used in the casserole.
Cheddar cheese is a classic choice. Feel free to substitute with Monterey Jack, mozzarella or any cheese you like! You can also leave the cheese out for a dairy free option.
Fajita seasoning - A homemade version is included but can be substituted with any store bought brand.
Salsa - Choose a thicker salsa to avoid your casserole turning out watery. Alternatively you can drain the salsa over a fine mesh sieve to remove any water.
Sour cream - This optional topping can be omitted or substituted with plain Greek yogurt or a dairy free alternative such as cashew cream.
Pickled jalapenos, avocado, and cilantro are all optional toppings. Other options include diced fresh tomatoes, sliced or diced fresh jalapeno peppers, and guacamole.
Variations
Make it vegetarian - Replace the chicken with a plant based protein such as tofu, black beans or chickpeas.
Make it creamy - Add ¼ cup of cream cheese or heavy cream to the filling before topping with cheese and baking.
How to make this recipe
Please see full instructions in the recipe card below.

- Step 1 - Fry the onions in oil over medium heat until beginning to soften.
- Step 2 - Push the onions to the outside and add the chicken into the center. Top with fajita seasoning and cook for 3 minutes before stirring. This helps prevent the chicken from sticking and allows it to start to brown.
- Step 3 - Stir everything together and continue cooking and stirring for 2 more minutes.
- Step 4 - Add the peppers and cook for 5 more minutes. Then add salsa and chopped cilantro and stir to combine.

- Step 5 - Top with grated mozzarella and pickled jalapeno slices, if using. Bake until cheese is melted and bubbling, about 15 minutes.
Frequently Asked Questions
Yes you can use beef, pork, or shrimp, in this recipe. However, the cooking time and method may need to be adjusted depending on the type of meat used. Shrimp should be added shortly before going into the oven to avoid overcooking.
Yes, you absolutely can! Store it in the refrigerator until you're ready to bake it. Let it come to room temperature for about 30 minutes before putting it in the oven.
Although typically made with peppers and onions you can add anything you like to this recipe such as zucchini, mushrooms and corn.
This recipe can easily be prepared in any frying pan and transfered to a casserole dish before being topped with cheese and baking. You can also prepare the recipe entirely on the stovetop. Top with cheese, cover and continue simmering until cheese is melted.
Storage
This casserole can be kept covered tightly or in an airtight container in the refrigerator for 3 to 4 days. Be sure to let it cool to room temperature before refrigerating.
To Freeze - You can freeze this recipe for up to 3 months. To reheat, let it thaw in the refrigerator overnight and then bake it in the oven according to the recipe instructions.

What to serve it with
There are many options to serve with this casserole.
- Tortilla shells - Flour or corn tortillas are a classic option that everyone loves.
- Lettuce boats - For a low-carb option serve in a lettuce boat.
- Rice - Serve your favourite rice for a more filling side option.
- Refried beans - Bump up the protein content by serving with refried beans.
- Salad - Get in some leafy greens with a crisp and fresh salad. It can provide a refreshing contrast to flavors and textures of this casserole.
- Condiments - Add some crunch and acidity with your own homemade Quick Pickled Carrots and Radish for something different.
More One-Pot Meals
Tried this recipe? I would love it if you could leave a star rating ⭐️⭐️⭐️⭐️⭐️ and/or a comment below. You can also follow me on social media here on Facebook, Instagram, and Pinterest!
📖 Recipe

Chicken Fajita Casserole
Ingredients
- 2 tablespoons avocado oil
- 3 chicken breasts cut into thin strips (740 g or 1 ½ pounds)
- 3 bell peppers sliced into ½ inch strips
- 1 large white onion
- 3 ¼ tablespoons Enchilada seasoning recipe below or 3 tablespoons store-bought
- 1 ¾ cups salsa (400 ml/
- 2 cups Cheddar cheese shredded
- 8 to 10 slices pickled jalapenos optional
- 3 green onions thinly sliced
- ¼ cup finely chopped fresh cilantro including stems, more leaves for garnish
Seasoning Mix (makes 3 ¼ tablespoons)
- 1 ½ teaspoons garlic powder
- 1 ½ teaspoons onion powder
- 3 teaspoons ground cumin
- 1 ½ teaspoons paprika
- ½ teaspoon dried oregano
- ¼ teaspoon cayenne pepper
- ½ teaspoon freshly ground black pepper
- 1 teaspoon salt
Optional Toppings
- Pickled jalapenos
- Sour cream or Greek yogurt
- Sliced or diced avocado
- Fresh lime wedges
- Cilantro leaves
Instructions
- Preheat oven to 350 degrees Fahrenheit.
- Heat oil in a large oven-proof skillet over medium-high heat. Add the onions and cook them for 2 minutes, stirring occasionally.
- Push the onions to the edges of the pan, and add the chicken strips to the center. Sprinkle the fajita seasoning over the chicken, and let it cook without stirring for 3 minutes.
- Stir everything together and cook for an additional 2 minutes, stirring occasionally. Then, add the peppers and continue cooking and stirring for 5 more minutes.
- Add salsa and chopped cilantro. Stir to combine.
- Remove the skillet from the heat, and sprinkle the top with cheddar cheese and pickled jalapenos (if using).
- Bake the skillet in the preheated oven for 15 minutes or until the cheese is bubbly and melted.
- Remove the skillet from the oven, and sprinkle the top with fresh cilantro and sliced green onions.
- Serve the chicken fajita casserole with any optional toppings of your choice.
Renae says
This recipe was so easy and so delicious! The only thing I will change next time is to reduce the salt in the seasoning. Thanks for another fantastic recipe Andrea!
Andrea says
I'm so happy you enjoyed it! The best thing about making your own seasonings is that you can adjust them to suit your needs 😃 Thanks for the comment!
Julie says
Made this for the first time tonight for company. They absolutely loved it and had seconds! Guaranteed it won’t be the last! This was absolutely delicious and so quick and easy to make. I have made so many of Andrea’s recipe and every single one is amazing! Keep on creating Andrea, I look forward to all of your new recipes. You rock Livy Loser!
Andrea says
I'm so happy you enjoyed the fajita casserole as well as others! Thanks so much for the comment 😊
Debbie says
This was amazing Andrea! I often make fajitas but not in a pan like this. It was so easy and quick. Everyone loved it too!
Thanks for all the great meals
Andrea says
I'm so happy you all enjoyed it! Thanks for commenting!
Jennifer Mendoza says
Hi Andrea!
This is another hit! It was so good!
Thank you
Jen
Charlene Gould says
Absolutely amazing😍 I served it on rice with Guacamole.I added some leftover corn and next time might add some black beans.
My whole family inhaled this dinner and everyone said this is definitely a do again recipe. Thanks Andrea❤️
Andrea says
I am so happy to hear the whole family enjoyed it! Great additions too 👌 Thanks so much for commenting!
Kirsten Kairis says
What is a substitute for a cast iron skillet? 🙂
Andrea says
Any oven proof skillet will work or you can transfer everything into a casserole dish. Hope you enjoy it!