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Chicken Fajita Casserole – Creamy, Cheesy & Packed With Bold Tex-Mex Flavor

This Chicken Fajita Casserole transforms classic sizzling fajitas into a warm, cheesy, oven-baked dish filled with juicy chicken, tender peppers, Tex-Mex spices, and a creamy melted topping. It’s the perfect weeknight comfort meal—simple to assemble, loaded with flavor, and ideal for serving over rice, stuffed into tortillas, or enjoyed straight from the baking dish.
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Ingredients Equipment Method Notes

Ingredients
  

For the Chicken & Veggies
  • 1 lb 450g cooked shredded or cubed chicken
  • 1 red bell pepper sliced
  • 1 green bell pepper sliced
  • 1 yellow onion sliced
For the Fajita Sauce
  • 1 cup sour cream or Greek yogurt
  • 1 cup salsa mild or spicy
  • 1 tbsp chili powder
  • 1 tsp cumin
  • 1 tsp paprika
  • ½ tsp garlic powder
  • ½ tsp onion powder
  • ½ tsp salt
  • ¼ tsp black pepper
  • 1 tbsp lime juice
For the Cheesy Topping
  • 1 ½ cups shredded cheddar or Mexican blend cheese
  • Optional: sliced jalapeños
  • Optional: chopped cilantro for garnish

Equipment

  • Cutting board
  • Knife
  • Large mixing bowl
  • Skillet (optional for pre-sautéing)
  • 9x13 casserole dish
  • Foil
  • Oven

Method
 

Step 1: Prep the Chicken & Vegetables
  1. Slice bell peppers and onions into thin strips. If the chicken isn’t cooked yet, quickly sauté or boil it and shred or cube it.
Step 2: Mix the Fajita Sauce
  1. In a large mixing bowl, whisk together sour cream, salsa, chili powder, cumin, paprika, garlic powder, onion powder, salt, pepper, and lime juice until creamy and well blended.
Step 3: Combine Everything
  1. Add the chicken, peppers, and onions into the bowl with the sauce. Toss until everything is fully coated.
Step 4: Fill the Casserole Dish
  1. Transfer the coated chicken and vegetables to a 9×13 baking dish, spreading into an even layer.
Step 5: Add the Cheese
  1. Sprinkle shredded cheddar or Mexican blend cheese evenly over the top. Add jalapeños if you want extra heat.
Step 6: Bake Until Bubbly
  1. Bake at 375°F (190°C) for 20–25 minutes, or until the casserole is hot and cheese is fully melted and bubbling.
Step 7: Garnish & Serve
  1. Remove from oven, top with fresh cilantro, and serve warm over rice, inside tortillas, or with tortilla chips.

Notes

🧊 Storage & Reheating
Store leftovers refrigerated for up to 3 days.
Reheat in microwave or oven at 350°F (175°C) for 10 minutes.
Freeze unbaked casserole (without cheese) for up to 2 months; add cheese before baking.
🥄 Variations
Creamy Ranch Fajita Casserole: Add 1 tbsp ranch seasoning to the sauce.
Low-Carb Version: Serve over cauliflower rice or eat on its own.
Veggie Boost: Add mushrooms, corn, or black beans.
Extra Spicy: Use hot salsa + chopped jalapeños + chili flakes.
Cheesy Queso Style: Replace ½ cup cheese with queso sauce.
❓ 10 FAQs
Can I use rotisserie chicken?
Yes—perfect time-saver.
Can I use raw chicken?
Dice it small and bake the casserole for 35–40 minutes.
Can I make it dairy-free?
Use dairy-free yogurt and dairy-free cheese.
What salsa works best?
Any—chunky, smooth, mild, or hot depending on flavor preference.
Can I add tortillas directly?
Yes—mix torn corn tortillas into the casserole for enchilada-like texture.
Why are my veggies watery?
Sauté peppers/onions first if you want them softer and drier.
Can I prepare it ahead?
Yes—assemble and refrigerate up to 24 hours before baking.
What cheese melts best?
Mexican blend, cheddar, Monterey jack, or pepper jack.
Can I use fajita seasoning instead of individual spices?
Absolutely—use 1–2 tablespoons.
How do I make it gluten-free?
The casserole is naturally gluten-free—just use GF sides.
🏁 Conclusion
This Chicken Fajita Casserole is creamy, cheesy, and packed with bold Tex-Mex flavor—all in one easy baked dish. Whether you scoop it into tortillas or enjoy it on its own, it delivers weeknight convenience and irresistible comfort in every bite.