Cheesy Chicken Fajita Casserole

The smell of peppers hitting a hot skillet still takes me back to my college apartment, where fajitas were the only dinner that felt fancy on a budget. My roommate and I would crowd around the stove, watching onions turn translucent while cheese bubbled in our tiny oven. This casserole captures that exact magic, but with the comfort of an all-in-one bake that feeds a crowd without the fuss of individual tortillas.

Last winter, I brought this to a friend's potluck when everyone was exhausted from the holiday rush. Within minutes, the casserole dish was empty, and three people asked for the recipe while scraping the last bits of cheese from the corners.

Ingredients

• 3 cups cooked chicken breast: Rotisserie chicken works beautifully here and saves so much prep time on busy weeknights
• 3 bell peppers (red, green, yellow): The mix of colors makes the dish look stunning and adds slightly different sweet notes
• 1 large onion: White onions become sweeter as they cook, balancing the spices perfectly
• 2 cups Mexican blend cheese: Shredding it yourself from blocks makes for meltier, gooier results
• 1/2 cup sour cream and 4 oz cream cheese: This duo creates the creamy base that holds everything together
• 10 oz diced tomatoes with green chilies: Drain them well so your casserole doesn't become soupy
• Chili powder, cumin, smoked paprika: These three form the holy trinity of fajita flavor
• Garlic powder, onion powder, cayenne: Layer in the heat gradually and taste as you go

Instructions

Prep your oven and dish:

Get your oven to 375°F and grease a 9x13-inch baking dish with butter or cooking spray

Sauté the vegetables:

Heat olive oil in a large skillet over medium-high heat, then cook your sliced peppers and onions for 6 to 8 minutes until they're soft and starting to caramelize

Combine everything:

Mix the cooked chicken, sautéed vegetables, diced tomatoes, all your spices, cream cheese, and sour cream in a large bowl until well combined

Assemble the casserole:

Spread the mixture evenly in your prepared dish and cover the top with shredded cheese

Bake until bubbly:

Cook uncovered for 25 to 30 minutes until the cheese is golden and the edges are bubbling hot

Rest and serve:

Let it sit for about 5 minutes before serving, which helps the layers set slightly

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My daughter now requests this for her birthday dinner every year, and I've learned to double the recipe because leftovers disappear even faster than the first serving.

Make It Your Own

Swap in turkey, leftover roast beef, or even make it vegetarian with extra peppers and black beans. The spice blend works just as beautifully with different proteins.

Timing Is Everything

You can assemble this casserole up to 24 hours ahead and refrigerate it before baking. Just add about 10 extra minutes to the baking time if it's cold from the fridge.

Serving Suggestions

Warm flour tortillas on the side let everyone scoop up their perfect bite, and a simple green salad with lime dressing cuts through the richness beautifully.

• Set out bowls of guacamole and extra salsa for a full fiesta spread
• Serve over cilantro lime rice if you want to stretch the servings even further
• Keep sliced jalapeños handy for the spice lovers at your table

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There's something deeply satisfying about a dish that brings everyone to the table faster than you can say dinner is ready.

Recipe FAQs

→ Can I use raw chicken instead of cooked?

Yes, you can use raw chicken. Cut boneless breasts into bite-sized pieces and cook them in the skillet with the peppers and onions until fully cooked through before combining with the other ingredients.

→ Can I make this ahead of time?

Absolutely. Assemble the casserole completely, cover tightly, and refrigerate for up to 24 hours before baking. You may need to add 5-10 minutes to the baking time if baking cold from the refrigerator.

→ What can I serve with this casserole?

Warm flour or corn tortillas, Spanish rice, refried beans, or a simple green salad make excellent sides. You can also top with additional sour cream, guacamole, or salsa for extra flavor.

→ Can I freeze this dish?

Yes, this freezes well. Assemble the unbaked casserole, wrap tightly in plastic and foil, and freeze for up to 3 months. Thaw overnight in the refrigerator before baking as directed.

→ How can I make it spicier?

Add diced jalapeños with the peppers, increase the cayenne pepper to 1/2 teaspoon, use pepper jack cheese in place of some Mexican blend, or serve with hot sauce on the side.