Dinner

Chicken Fajita Casserole Recipe

ByHugo Harnd February 9, 2026February 9, 2026

Introduction

This Chicken Fajita Casserole is an easy, flavorful dish that combines tender chicken, colorful bell peppers, and melted cheese in one pan. Perfect for busy weeknights, it brings all the flavors of fajitas into a comforting baked meal.

A close-up of a silver spoon lifting a layered mix of melted cheese, bright red bell pepper strips, and light golden cooked onions from a white plate, showing rich texture with stretchy, gooey yellow and white cheese that is slightly browned at the edges and sprinkled with small green herbs. The layers include the cooked onion at the bottom, soft red pepper slices in the middle, and bubbly melted cheese draped on top. The background shows more of the cheesy, colorful mix in the plate, resting on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Ingredients

1 ½ pounds boneless skinless chicken breasts (split lengthwise, or chicken thigh)
3 bell peppers (red, yellow, or green, seeded and sliced into strips)
1 large yellow onion (or two medium onions, or white onion)
1 tablespoon olive oil
8 oz Jack cheese (shredded, or cheddar or Havarti, about 2 cups)
Fresh cilantro (optional garnish)
1 teaspoon cumin powder
2 teaspoons chili powder
1 ½ teaspoons garlic powder
2 teaspoons paprika
Salt and pepper (to taste)

Instructions

Preheat the oven: Set your oven to 400°F (200°C) and position the rack in the lower middle. Use convection mode if your oven has it for even cooking.
Prepare the pan: Lightly grease a 9×13-inch baking dish with olive oil. Arrange the split chicken breasts in a single layer in the dish.
Add the seasoning: In a small bowl, mix cumin, chili powder, garlic powder, paprika, salt, and pepper. Drizzle olive oil over the chicken and sprinkle half of the seasoning mix evenly on top.
Add the vegetables: Spread the sliced onions and bell peppers over the chicken. Sprinkle the remaining seasoning mix evenly over the vegetables.
Bake in the oven: Top the casserole with shredded cheese. Bake uncovered for 20-25 minutes, or until the chicken reaches an internal temperature of 160°F (use an instant-read thermometer).
Garnish and serve: Remove from oven and garnish with fresh cilantro if desired. Serve warm and enjoy!

Tips & Variations

For richer flavor, substitute chicken breasts with boneless skinless chicken thighs.
Add sliced jalapeños for a spicy kick.
Use a mix of cheeses like cheddar and Havarti for different flavor profiles.
Serve with warm tortillas, sour cream, or avocado for a complete fajita experience.

Storage

Store leftover casserole in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F until warmed through to keep the chicken tender and cheese melty. Avoid microwaving to maintain texture.

How to Serve

A close-up of a baked dish in a white rectangular casserole dish filled with melted cheese covering soft, cooked red bell pepper strips, showing some golden brown spots and slight charring, garnished with small bits of green herbs scattered over the top. The layers include a base layer of cooked red bell peppers with a rich, melted, bubbly cheese layer on top that has a mix of creamy white and light orange colors. The texture looks gooey and stretchy with some crispy edges. The dish sits on a white marbled surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use frozen chicken for this recipe?

It’s best to use fresh or fully thawed chicken breasts to ensure even cooking and proper internal temperature. Cooking from frozen may result in unevenly cooked meat.

Can I prepare this casserole ahead of time?

Yes, you can assemble the casserole a few hours before baking and keep it covered in the refrigerator. Bake it when ready, adding a few extra minutes to cooking time if chilled.