Cheesy Chicken Fajita Casserole

Rainy Tuesday nights have become my favorite excuse to make this casserole. The way the peppers and onions caramelize in the skillet fills the entire house with this incredible aroma that makes everyone wander into the kitchen asking whats for dinner. My youngest started calling it taco pie and now requests it by that name every single week.

Last summer I made this for a potluck when I completely forgot about the gathering until two hours before. I grabbed a rotisserie chicken from the store and threw everything together. Three different people asked for the recipe and now its my go to emergency dish that always feels intentional and special.

Ingredients

• 3 cups cooked chicken breast: Rotisserie chicken works perfectly here and saves so much time or bake some ahead and keep it in the fridge
• 3 large bell peppers one red one green one yellow: The mix of colors looks gorgeous and each variety brings its own subtle sweetness to the dish
• 1 large onion sliced: Yellow onions caramelize beautifully but red onions work too if you prefer a slightly sharper flavor
• 2 cups shredded Mexican blend cheese: I use the pre shredded blend from the store but Monterey Jack mixed with cheddar is amazing too
• 1/2 cup sour cream: Full fat tastes best but low fat works if thats what you keep on hand
• 4 oz cream cheese softened: Let it sit on the counter while you prep everything else so it blends easily
• 1 can (10 oz) diced tomatoes with green chilies drained: Do not skip the draining step or your casserole will be too soupy
• 1 tsp chili powder: This gives that classic Tex Mex warmth without being too spicy
• 1 tsp ground cumin: The secret ingredient that makes everything taste like fajitas
• 1/2 tsp smoked paprika: Regular paprika works in a pinch but smoked adds this incredible depth
• 1/2 tsp garlic powder: Fresh garlic burns too easily in this dish so powder works better here
• 1/2 tsp onion powder: Boosts the onion flavor throughout the whole casserole
• 1/4 tsp cayenne pepper optional: Leave it out for sensitive palates or double it if your family loves heat
• Salt and black pepper: Taste the mixture before baking and adjust since seasoning needs vary
• 1 tbsp olive oil: For sautéing the veggies butter works too if you prefer
• Fresh cilantro and green onions optional: These add such a fresh pop against the rich cheese

Instructions

Preheat your oven:

Get it to 375°F (190°C) 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 cook those sliced peppers and onions for about 8 minutes until theyre soft and starting to get those gorgeous browned edges.

Mix everything together:

In a big bowl combine the chicken cooked veggies diced tomatoes all those spices sour cream and cream cheese until everything is well coated.

Assemble the casserole:

Spread the mixture into your prepared dish and sprinkle all that cheese evenly across the top.

Bake until bubbly:

Pop it in the oven for 25 to 30 minutes until the cheese is melted and golden and you can see the sauce bubbling up around the edges.

Let it rest and serve:

Wait about 5 minutes before serving so it sets up slightly then top with fresh cilantro and green onions if you want.

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My neighbor came over once when this was in the oven and actually asked what Mexican restaurant I had ordered from. We ended up eating together on the back porch and now whenever I make it I text her to come over. Some recipes are just meant to be shared.

Make It Your Own

I have tried so many variations of this depending on what is in the fridge. Sometimes I add black beans or corn for extra texture. Leftover taco meat works surprisingly well instead of chicken. The beauty is that the spice blend makes everything taste like it belongs together.

Perfect Sides

Warm flour tortillas on the side turn this into the ultimate comfort meal. A simple green salad with lime vinaigrette cuts through all that cheese perfectly. My husband insists on serving it over Mexican rice but honestly it stands completely on its own.

Make Ahead Magic

You can assemble the entire casserole up to 24 hours before baking and keep it covered in the refrigerator. The flavors actually meld together even more this way. Just add about 10 extra minutes to the baking time since it will be cold going into the oven.

• Wrap the dish tightly with foil before refrigerating to prevent the top from drying out
• Let it sit on the counter for 30 minutes while the oven preheats to promote even cooking
• The casserole freezes beautifully for up to 3 months just thaw before baking

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There is something so satisfying about a casserole that delivers all those restaurant flavors with almost zero effort. This one has earned its permanent spot in my weekly rotation and I bet it will find its way into yours too.

Recipe Questions & Answers

→ Can I use rotisserie chicken for this casserole?

Yes, rotisserie chicken works wonderfully and saves time. Simply shred about 3 cups of the cooked chicken and proceed with the recipe as directed.

→ Can I prepare this casserole ahead of time?

Absolutely. Assemble the entire casserole, cover tightly, and refrigerate for up to 24 hours before baking. You may need to add a few extra minutes to the baking time if baking cold from the refrigerator.

→ What can I serve with this fajita casserole?

Warm flour or corn tortillas, Spanish rice, refried beans, or a simple green salad make excellent sides. Fresh guacamole and salsa also complement the flavors beautifully.

→ How can I make this casserole spicier?

Increase the cayenne pepper to 1/2 teaspoon, add diced jalapeños to the vegetable mixture, or use pepper jack cheese in place of some of the Mexican blend cheese.

→ Can I freeze this casserole?

Yes, you can freeze the assembled, unbaked casserole for up to 3 months. Thaw overnight in the refrigerator before baking, or bake from frozen adding about 15-20 minutes to the cooking time.

→ What other proteins work in this casserole?

Shredded turkey, cooked ground beef, or even pulled pork make great alternatives. Just ensure the meat is fully cooked before mixing with the other ingredients.