Cheesy Chicken Fajita Casserole

It was a rainy Tuesday when my friend Sarah dropped by unexpectedly with a rotisserie chicken and said we needed to turn it into something spectacular. We ended up throwing together this casserole on a whim, and the way those peppers caramelized in the skillet before hitting the oven changed everything I thought I knew about fajitas.

Last winter, my neighbor texted me at 5 PM saying she needed something comforting but had zero energy. I brought over a batch of this casserole still warm from the oven, and she called me two days later asking for the recipe because her kids had requested it again. Thats when I knew this wasnt just dinner, it was a problem solver.

Ingredients

• Cooked Chicken Breast: Rotisserie chicken works beautifully here, or use leftover roasted chicken
• Bell Peppers: The trio of red, green, and yellow gives you sweetness and that classic fajita pop of color
• Onion: Yellow onion becomes sweet and mellow when sautéed, balancing the spices
• Mexican Blend Cheese: A mix of cheddar, Monterey Jack, and asadero melts into that perfectly gooey topping
• Sour Cream: Adds tanginess and helps create the creamy base sauce
• Cream Cheese: The secret ingredient that makes the filling impossibly rich
• Diced Tomatoes with Green Chilies: Draining them keeps the casserole from getting watery while still delivering flavor
• Chili Powder and Cumin: These two spices are the backbone of traditional fajita seasoning
• Smoked Paprika: Gives you that subtle smoky depth without firing up the grill
• Garlic and Onion Powder: Layer in savory notes that bloom during baking
• Cayenne Pepper: Optional, but add it if you like things with a little kick
• Olive Oil: Helps the vegetables caramelize beautifully in the skillet
• Fresh Cilantro and Green Onions: These bright garnishes cut through all that rich cheese

Instructions

Preheat and Prep:

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 and add sliced peppers and onions. Cook for 6 to 8 minutes until soft and starting to caramelize at the edges, then remove from heat.

Mix the Filling:

In a large bowl, combine shredded chicken, sautéed vegetables, diced tomatoes with green chilies, all the spices, cream cheese, and sour cream. Season generously with salt and pepper.

Assemble the Casserole:

Spread the mixture evenly in your prepared baking dish and sprinkle the shredded Mexican cheese all over the top.

Bake Until Golden:

Bake uncovered for 25 to 30 minutes until hot and bubbly with golden brown spots on the cheese.

Rest and Serve:

Let the casserole sit for about 5 minutes before serving, then garnish with fresh cilantro and green onions if you like.

Save to Pinterest

My sister claimed she didnt like casseroles until I made this for her birthday dinner. She took three servings and asked to take the leftovers home, which is basically the highest compliment possible in our family.

Make Ahead Magic

You can assemble the entire casserole up to 24 hours before baking and keep it covered in the refrigerator. Just add 5 to 10 minutes to the baking time since it will be cold going into the oven.

Serving Ideas

Warm flour tortillas on the side turn this into fork fajitas. Or serve over cilantro lime rice for a heartier meal. A crisp green salad with citrus vinaigrette cuts through the richness beautifully.

Storage and Reheating

Leftovers keep well in an airtight container for up to 4 days. Reheat individual portions in the microwave at 50 percent power to prevent the cheese from separating. Cover with a damp paper towel for best results.

• Freeze unbaked casseroles for up to 3 months
• Thaw overnight in the refrigerator before baking
• Add extra cheese before reheating to refresh the topping

Save to Pinterest

This is the kind of dinner that makes people feel taken care of, and isnt that what cooking is really about?

Recipes Q&A

→ Can I make this ahead of time?

Yes, 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 tortillas, Spanish rice, or a simple green salad complement this dish perfectly. You can also serve with guacamole, salsa, or extra sour cream on the side.

→ Can I use rotisserie chicken?

Absolutely. Using a store-bought rotisserie chicken is a great shortcut. Simply shred or cube about 3 cups of meat and add it directly to the mixture.

→ How do I store leftovers?

Store cooled leftovers in an airtight container in the refrigerator for 3-4 days. Reheat individual portions in the microwave or cover the entire dish with foil and warm in a 350°F oven.

→ Can I freeze this casserole?

Yes, you can freeze this either before baking (wrap tightly) or after baking and cooling. Thaw overnight in the refrigerator before baking or reheating. Best enjoyed within 3 months.