Cheesy Chicken Fajita Casserole

The smell of peppers hitting hot oil takes me back to my first apartment, where I learned that fajitas don't need a sizzling skillet to taste incredible. My roommate walked in while this was baking and immediately asked what restaurant I'd ordered from. That moment of pulling bubbling, cheese-topped perfection from the oven still makes me smile.

I made this for a friend who claimed she hated casseroles, and she went back for thirds. There's something about that combination of tender chicken, sweet peppers, and melty cheese that feels like a hug in a baking dish. Now it's my go-to when I need to feed a crowd without spending hours at the stove.

Ingredients

• 3 cups cooked chicken breast: Rotisserie chicken works perfectly here, just shred it with forks or cube it into bite sized pieces
• 3 large bell peppers: Using red, green, and yellow gives you beautiful color variance and slightly different sweetness levels
• 1 large onion: Yellow onion becomes perfectly sweet when sautéed, balancing the spices
• 2 cups shredded Mexican blend cheese: This melts better than cheddar alone and gives you that classic Tex Mex flavor
• 1/2 cup sour cream: Adds tanginess and keeps the chicken incredibly moist during baking
• 4 oz cream cheese: The secret ingredient that makes the sauce creamy and helps everything bind together
• 1 can diced tomatoes with green chilies: Drain well so your casserole doesn't become watery
• Chili powder, cumin, smoked paprika, garlic powder, onion powder, and cayenne: This combination creates that signature fajita seasoning blend
• 1 tbsp olive oil: For sautéing your vegetables until they're perfectly softened

Instructions

Preheat your oven:

Get it to 375°F and grease a 9x13 baking dish with butter or cooking spray

Sauté the vegetables:

Heat olive oil in a large skillet over medium high heat, add sliced peppers and onions, cook 6 to 8 minutes until soft and slightly caramelized

Mix everything together:

In a large bowl, combine chicken, cooked vegetables, diced tomatoes, all spices, cream cheese, and sour cream until well combined, then season generously with salt and pepper

Assemble the casserole:

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

Bake until bubbly:

Cook uncovered for 25 to 30 minutes until hot throughout and the cheese is golden brown in spots

Rest and garnish:

Let it sit for 5 minutes before serving, sprinkle with fresh cilantro and green onions if you want that restaurant style finish

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My niece who refuses to eat anything with peppers tried this and immediately asked for the recipe. Now whenever she visits, this casserole is nonnegotiable. Food has this magical way of bringing people together, especially when it's comfort food this good.

Make Ahead Magic

You can assemble this entire casserole up to 24 hours before baking, just cover it tightly and refrigerate. When you're ready to bake, add about 10 extra minutes to the cooking time since it will be cold.

Serving Suggestions

Warm flour tortillas on the side turn this into an interactive meal, or serve over cilantro lime rice for a complete bowl. A simple green salad with tangy vinaigrette cuts through the richness beautifully.

Spice It Your Way

This recipe is perfectly forgiving when it comes to heat levels. The cayenne is entirely optional, and you can add diced jalapeños or a splash of hot sauce to the mixture before baking.

• Mild palates can skip the cayenne entirely
• Medium spice lovers might add a diced jalapeño with the peppers
• Heat seekers can double the cayenne and serve with extra hot sauce

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This casserole has become my answer to everything from Tuesday night dinners to potluck contributions. Hope it finds a regular spot in your rotation too.

Recipe Help & Support

→ Can I use rotisserie chicken for this casserole?

Yes, rotisserie chicken works perfectly and saves time. Simply shred about 3 cups of meat and add it directly to the mixture.

→ How spicy is this casserole?

The dish has mild to medium heat. You can control the spice level by adjusting the cayenne pepper or adding diced jalapeños for extra kick.

→ Can I make this casserole ahead of time?

Absolutely. Assemble the entire dish, cover tightly, and refrigerate for up to 24 hours before baking. Add 5-10 minutes to the baking time if baking cold from the refrigerator.

→ What should I serve with this casserole?

Warm tortillas, Mexican rice, or a simple green salad complement this dish well. You can also top with avocado, sliced jalapeños, or a dollop of sour cream.

→ Can I freeze this casserole?

Yes, freeze before baking. Wrap tightly in plastic and foil for up to 3 months. Thaw overnight in the refrigerator before baking as directed.

→ What vegetables work best in this casserole?

Bell peppers and onions are traditional, but you can add poblano peppers, corn, or black beans for extra texture and flavor.