Dinner

Cheesy Oven-Baked Chicken Fajita Casserole Recipe

Name: Cheesy Oven-Baked Chicken Fajita Casserole Recipe
Prep time: 15 min
Cook time: 35 min
Total time: 50 min
Cuisine: Tex-Mex
Ingredients: 1.5 pounds boneless, skinless chicken breasts or thighs, cut into strips; 3 large bell peppers (red, yellow, green), sliced; 1 large onion, sliced; 2 cups shredded cheese (cheddar, Monterey Jack, or pepper jack); 10 oz diced tomatoes with green chilies, drained; 2 tbsp olive oil; 1 lime, juiced; Fresh cilantro, chopped (for garnish); 2 tsp chili powder; 1 tsp smoked paprika; 1 tsp ground cumin; 1 tsp garlic powder; 1 tsp onion powder; 0.5 tsp dried oregano; 0.25 tsp cayenne pepper (adjust to taste); Salt and black pepper to taste

ByNaomi Fletcher March 4, 2026March 4, 2026

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Introduction

Chicken Fajita Casserole brings all the vibrant, smoky flavors of traditional Tex-Mex fajitas into an easy, one-pan oven-baked meal. It combines tender, seasoned chicken with colorful bell peppers, onions, and melted cheese for a comforting dinner perfect for busy weeknights or casual gatherings.

Ingredients

1 ½ pounds boneless, skinless chicken breasts or thighs, cut into strips
3 large bell peppers (red, yellow, green), sliced
1 large onion, sliced
2 cups shredded cheese (cheddar, Monterey Jack, or pepper jack)
1 can (10 oz) diced tomatoes with green chilies, drained
2 tbsp olive oil
Juice of 1 lime
Fresh cilantro, chopped (for garnish)

Homemade Fajita Seasoning:

2 tsp chili powder
1 tsp smoked paprika
1 tsp ground cumin
1 tsp garlic powder
1 tsp onion powder
½ tsp dried oregano
¼ tsp cayenne pepper (adjust to taste)
Salt and black pepper to taste

Instructions

Step 1: Preheat your oven to 400°F (200°C) and lightly grease a 9×13-inch baking dish.
Step 2: In a large bowl, toss the chicken strips with olive oil, lime juice, and the homemade fajita seasoning. Let it marinate for at least 10–15 minutes to soak in the flavors.
Step 3: Add the sliced bell peppers and onion to the bowl, tossing everything together so it is evenly coated.
Step 4: Spread half of the chicken and vegetable mixture in the prepared baking dish. Top with half of the drained diced tomatoes and 1 cup of shredded cheese. Repeat with the remaining chicken mixture, tomatoes, and cheese.
Step 5: Cover the dish with foil and bake for 20 minutes. Remove the foil and bake for an additional 10–15 minutes, until the cheese is melted and golden.
Step 6: Optional: Broil the casserole for 2–3 minutes at the end to achieve extra browning on top.
Step 7: Let the casserole rest for 5 minutes, then garnish with fresh cilantro and serve with warm tortillas or rice.

Tips & Variations

Marinate the chicken and prep vegetables up to 24 hours ahead for deeper flavor and easier assembly.
Add black beans, roasted corn, or sliced jalapeños to the mix for extra texture and variety.
Try using a mix of cheeses like Monterey Jack and pepper jack for a meltier, spicier casserole.
For a vegetarian version, substitute chicken with sautéed mushrooms, black beans, and zucchini.
Serve over cauliflower rice or sautéed greens for a low-carb option.

Storage

Store leftover casserole in an airtight container in the refrigerator for up to 3–4 days. Reheat gently in the oven or microwave until warmed through. You can also assemble the casserole in advance and refrigerate for up to 24 hours before baking. For longer storage, freeze unbaked casserole for up to 3 months; thaw overnight before baking.

How to Serve

A close-up of a black pan filled with three main layers: the bottom layer has cooked black beans, chopped vegetables like green and red peppers with a soft texture; the middle layer is covered in smooth, melted white cheese with a slightly browned surface and small black pepper specks; the top layer includes golden-brown crispy crumbles scattered around and fresh green cilantro leaves placed in the center, with a light wooden spoon scooping some cheesy parts. All this is set on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

How do I improve the flavor of chicken fajita casserole?

Use a homemade fajita seasoning with fresh spices and marinate the chicken in lime juice and seasoning for at least 30 minutes or overnight. Adding roasted bell peppers and onions enhances natural sweetness and depth of flavor. Finish the casserole with fresh cilantro and lime juice for brightness.

Can I make this chicken fajita casserole ahead of time?

Yes, you can assemble it in the baking dish and refrigerate for up to 24 hours before baking. It also freezes well unbaked for up to 3 months. Simply thaw overnight and bake as directed. Leftovers reheat beautifully for quick lunches or dinners.