Name: Chicken Fajita Casserole
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: Mexican
Ingredients: 1 lb chicken breast, boneless and skinless, cut into bite-sized pieces; 2 tablespoons olive oil; 1 red bell pepper, sliced; 1 green bell pepper, sliced; 1 onion, sliced; 1 packet (1 oz) fajita seasoning; 1 cup cooked brown rice; 1 can (14.5 oz) diced tomatoes, drained; 1 cup shredded cheddar cheese; 1 cup shredded mozzarella cheese; Salt and pepper to taste; Fresh cilantro, chopped (optional for garnish)

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A savory, cheesy, and flavorful casserole with all the deliciousness of chicken fajitas, perfect for a weeknight dinner. This dish layers tender chicken, peppers, and onions with a tasty blend of spices and cheese for a satisfying, family-friendly meal.

Why You'll Love This Recipe

This Chicken Fajita Casserole brings all the beloved flavors of sizzling fajitas into a convenient, oven-baked dish. It's perfect for busy weeknights when you crave Mexican-inspired flavors but don't have time to prepare individual fajitas. The combination of juicy chicken, colorful bell peppers, and gooey cheese creates a meal that's both nutritious and satisfying. Plus, it's versatile enough to please picky eaters while still delivering authentic fajita flavor. This casserole also makes excellent leftovers, meaning you can enjoy this delicious meal for days to come.

Ingredients

(Tip: You'll find the full list of ingredients and measurements in the recipe card below.)

Chicken breast provides lean protein and becomes tender and juicy when baked in this casserole. It absorbs the fajita seasonings beautifully, making each bite flavorful. You can substitute with chicken thighs for even more moisture if preferred.

Olive oil helps brown the chicken and sauté the vegetables, adding a subtle richness to the dish. Any neutral cooking oil would work in a pinch.

Bell peppers add vibrant color, sweetness, and essential vitamins to the casserole. The combination of red and green creates visual appeal, but you can use any color bell peppers you have available. For extra heat, consider adding some jalapeños.

Onion provides aromatic depth and sweetness when caramelized slightly before baking. Yellow onions work best, but red onions can add a pop of color and slightly different flavor profile.

Fajita seasoning is the flavor backbone of this dish, providing that authentic Mexican-inspired taste with cumin, chili powder, garlic, and other spices. You can use store-bought packets for convenience or make your own blend at home for more control over the spice level.

Brown rice adds hearty texture and nutritional value with its fiber content. It also helps absorb the flavorful juices released during baking. White rice works perfectly fine as a substitute if that's what you have on hand.

Diced tomatoes contribute moisture and acidity that balances the rich cheese and savory spices. The slight tang brings brightness to the casserole.

Cheddar cheese provides sharp flavor and that classic golden-brown top when melted. It's a familiar taste that makes this dish universally appealing.

Mozzarella cheese creates those irresistible cheese pulls when served hot from the oven. Its mild flavor complements the bolder cheddar and doesn't compete with the fajita seasonings.

Cilantro brings a fresh, citrusy note that cuts through the richness of the casserole. It's optional but highly recommended for authentic fajita flavor.

Directions

Preheat oven to 375°F (190°C).
In a large skillet, heat olive oil over medium heat. Add chicken pieces and cook until browned and cooked through, about 5-7 minutes.
Add the sliced bell peppers and onion to the skillet with the chicken, and cook for 5 minutes until the vegetables start to soften.
Sprinkle the fajita seasoning over the chicken and vegetable mixture, stirring to coat. Add the drained diced tomatoes and cooked rice, then season with salt and pepper to taste. Stir to combine.
Transfer the chicken fajita mixture into a greased 9x13-inch baking dish.
Top with shredded cheddar and mozzarella cheese, spreading it evenly across the top.
Bake for 20-25 minutes, or until the cheese is melted and bubbly.
Remove from oven and garnish with chopped cilantro, if desired. Serve warm.

Servings and Timing

This Chicken Fajita Casserole makes 6 generous servings, making it perfect for a family meal with potential leftovers. It takes approximately 15 minutes to prep, 30 minutes to cook, for a total time of 45 minutes from start to finish. Each serving contains approximately 350 calories, offering a balanced meal with protein, carbohydrates, and vegetables all in one dish.

Variations

Vegetarian Fajita Casserole: Replace the chicken with a 15 oz can of black beans (drained and rinsed) and add 1 cup of corn for a delicious meatless alternative.

Spicy Chicken Fajita Casserole: Add 1-2 diced jalapeños or a 4 oz can of diced green chiles to the vegetable mixture for an extra kick of heat.

Low-Carb Option: Substitute the rice with cauliflower rice to reduce carbohydrates while maintaining volume and texture.

Creamy Fajita Casserole: Mix in ½ cup of sour cream to the chicken and vegetable mixture before baking for a creamier texture.

Tex-Mex Variation: Add 1 can of corn and 1 can of black beans to the mixture for a heartier, Tex-Mex inspired casserole.

Storage/Reheating

Refrigeration: Store leftover Chicken Fajita Casserole in an airtight container in the refrigerator for up to 4 days. Make sure the casserole has cooled completely before refrigerating.

Freezing: This casserole freezes exceptionally well. Portion into individual servings or freeze the entire casserole (prior to baking) for up to 3 months. If freezing a whole casserole, wrap it tightly in aluminum foil and place in a freezer bag to prevent freezer burn.

Reheating: For refrigerated leftovers, reheat individual portions in the microwave for 1-2 minutes or until heated through. For larger portions, reheat in a 350°F oven for 15-20 minutes, covered with foil to prevent the cheese from burning. If reheating from frozen, bake covered at 350°F for about 30-35 minutes, then uncovered for 10 minutes to crisp the top.

Meal Prep: This casserole is excellent for meal prep. Prepare the entire dish through step 5, refrigerate, and add the cheese just before baking the next day. This saves time and ensures fresh-tasting results.

FAQs

Can I use pre-cooked chicken for this recipe?

Yes, pre-cooked chicken works well in this recipe and will save you time. Rotisserie chicken is an excellent option—simply shred or dice about 2-3 cups and add it with the vegetables after they've softened. Adjust the cooking time in the skillet accordingly, as you'll only need to warm the chicken through rather than fully cook it.

Is it necessary to cook the rice before adding it to the casserole?

Yes, the rice must be pre-cooked before adding it to the casserole mixture. Uncooked rice would not have enough liquid or time to cook properly during the baking process, resulting in a crunchy texture. Cook the rice according to package directions before incorporating it into the casserole.

Can I make this casserole ahead of time?

Absolutely! You can prepare the entire casserole up to the point of baking, cover it tightly, and refrigerate for up to 24 hours. When ready to serve, let it sit at room temperature for about 30 minutes before baking, and you may need to add 5-10 minutes to the baking time if it's still cold from the refrigerator.

What can I serve with Chicken Fajita Casserole?

This casserole works wonderfully with simple sides like a green salad, avocado slices, or tortilla chips. You can also serve it with warm tortillas, allowing people to make wraps with the casserole filling. Additional toppings like sour cream, guacamole, or pico de gallo complement the flavors nicely.

How can I make this recipe spicier?

To increase the heat level, you can add diced jalapeños or a few dashes of hot sauce to the vegetable mixture. Using pepper jack cheese instead of part or all of the cheddar will also add a pleasant kick. Serving with hot sauce on the side allows each person to adjust the spice level to their preference.

Can I use flour tortillas in this recipe?

Yes, you can incorporate flour tortillas for a different texture. Try tearing 4-6 tortillas into pieces and layering them with the chicken mixture, creating a lasagna-like structure. You can place a layer of tortillas on the bottom of the dish, add half the chicken mixture, another layer of tortillas, the remaining chicken mixture, and top with cheese.

Is this recipe gluten-free?

The recipe as written can be gluten-free if you use a gluten-free fajita seasoning packet (some brands contain wheat fillers). Always check your seasoning packet ingredients or make your own fajita seasoning with gluten-free spices. All other ingredients are naturally gluten-free.

Can I use different cheeses in this recipe?

Definitely! While the combination of cheddar and mozzarella provides a good balance of flavor and meltability, you can experiment with other cheeses. Monterey Jack, pepper jack, or a Mexican cheese blend would all work well. For extra flavor, a sprinkle of cotija cheese on top after baking adds an authentic touch.

How do I know when the casserole is done baking?

The casserole is done when the cheese is completely melted and bubbly, with some golden-brown spots appearing on top. The edges should be slightly crispy, and when you insert a knife into the center, it should feel hot. If you're uncertain, you can use a food thermometer—the internal temperature should reach at least 165°F.

Can I make this recipe in a slow cooker?

Yes, this recipe adapts well to a slow cooker. Brown the chicken first, then combine all ingredients except the cheese in the slow cooker. Cook on low for 3-4 hours, add the cheese during the last 30 minutes, and cover until melted. Note that you won't get the same crispy, browned cheese top as with oven baking.

Conclusion

This Chicken Fajita Casserole transforms the vibrant flavors of traditional fajitas into a convenient, family-friendly dish that's perfect for busy weeknights or casual entertaining. The combination of tender chicken, colorful peppers, and melty cheese creates a satisfying meal that brings everyone to the table. What makes this recipe truly special is its versatility—you can easily adjust the spice levels, swap ingredients based on what you have on hand, or prepare it ahead of time for stress-free meal planning. Whether you're looking for a new way to enjoy Mexican-inspired flavors or need a reliable dish that pleases both adults and children alike, this casserole delivers on all fronts. Give it a try the next time you're craving fajitas but want the convenience of a one-dish meal—your family will be asking for seconds!