Chicken Fajita Casserole is a fun and easy twist on classic fajitas all baked in one dish. With tender pieces of chicken, colorful bell peppers, onions, and a mix of spices, it’s bursting with flavor and super satisfying. The melted cheese on top adds just the right touch of gooey goodness that everyone loves.
I really like making this casserole when I want all the tasty fajita flavors but without the extra work of assembling tortillas and toppings separately. It’s one of those meals that feels a little special but comes together quickly. I usually throw in extra peppers because I love the crunch and brightness they bring.
For serving, I enjoy topping it with a dollop of sour cream and a sprinkle of fresh cilantro. Sometimes I add some avocado slices or a squeeze of lime for a fresh kick. It’s a dish that works great for weeknight dinners or casual gatherings, and I love how it keeps warm and ready to scoop for everyone to enjoy.
Key Ingredients & Substitutions
Chicken: Boneless, skinless chicken breasts or thighs work well here. Thighs add more moisture and flavor, but breasts are leaner. If you prefer, cooked rotisserie chicken can save time and tastes great.
Bell Peppers & Onion: The colorful bell peppers offer sweetness and crunch. Feel free to mix in any colors you like, or add extra veggies like zucchini or mushrooms for variety.
Spices: Chili powder, cumin, and smoked paprika give the fajita flavor. If you don’t have smoked paprika, regular paprika or chipotle powder can add a smoky kick. Adjust the chili powder for your heat preference.
Cheese: Cheddar and Monterey Jack melt well, creating a creamy topping. You can swap for mozzarella or a Mexican cheese blend. For a dairy-free option, use plant-based cheese alternatives.
Salsa: Salsa brings moisture and tang. Use your favorite kind—mild, medium, or spicy. If you don’t have salsa, diced tomatoes mixed with a little chili powder can substitute.
How Do You Cook the Chicken and Peppers Perfectly for Fajita Casserole?
Cooking the chicken and peppers evenly is key for great flavor and texture.
- Heat oil in a large skillet over medium-high heat for a nice sear.
- Add peppers and onions first; cook just until they start softening but still slightly crisp, about 5 minutes.
- Add the chicken with spices, stirring often to coat everything well and cook through (6-8 minutes).
- Don’t overcrowd the pan—cook in batches if needed so everything browns nicely instead of steaming.
- Stir in salsa last to coat the mix and heat through before baking.
These steps keep the veggies tender yet vibrant and the chicken juicy, making the casserole tasty all the way through.
Equipment You’ll Need
- 9×9-inch (23×23 cm) baking dish – I find it’s the perfect size to hold all the ingredients without crowding.
- Large skillet – helps you cook the chicken and vegetables evenly and quickly.
- Wooden spoon or spatula – for stirring the spices and mixing everything well.
- Measuring cups and spoons – makes sure you add the right amount of seasonings and salsa.
- Oven – needed to melt the cheese and bake the casserole to bubbly perfection.
Flavor Variations & Add-Ins
- Use cooked leftover steak or shrimp instead of chicken for a different protein. It’s quick and adds a new flavor.
- Top with a sprinkle of feta or pepper jack cheese for a different cheesy flavor.
- Add chopped jalapeños or a splash of hot sauce in the mix if you like extra spice.
- Stir in sliced black olives or corn for added texture and flavor.
Chicken Fajita Casserole
Ingredients You’ll Need:
- 1 ½ lbs (680 g) boneless, skinless chicken breasts or thighs, cut into bite-sized pieces
- 1 each red, green, and orange bell pepper, thinly sliced
- 1 medium onion, thinly sliced
- 2 tbsp olive oil or vegetable oil
- 1 tbsp chili powder
- 1 tsp ground cumin
- 1 tsp smoked paprika
- ½ tsp garlic powder
- ½ tsp onion powder
- ½ tsp dried oregano
- ½ tsp salt (adjust to taste)
- ¼ tsp black pepper
- 1 cup salsa (mild or medium heat)
- 1 cup shredded cheddar cheese
- 1 cup shredded Monterey Jack cheese
- Fresh cilantro, chopped (for garnish)
- Sour cream (for serving)
Time Needed
This recipe takes about 10 minutes to prep, 15 minutes to cook the chicken and veggies on the stove, and about 15-20 minutes to bake until the cheese is melted and bubbly. So, plan for around 40-45 minutes total from start to finish.
Step-by-Step Instructions:
1. Prepare and Cook the Vegetables:
Preheat your oven to 375°F (190°C) and lightly grease a 9×9-inch (23×23 cm) baking dish. Heat the oil in a large skillet over medium-high heat. Add the sliced bell peppers and onion and sauté for about 5 minutes until they start to soften but still have some crunch.
2. Cook the Chicken and Add Seasonings:
Add the chicken pieces to the skillet with the veggies. Sprinkle all the spices evenly over the mixture—chili powder, cumin, smoked paprika, garlic powder, onion powder, oregano, salt, and black pepper. Stir well and cook for 6-8 minutes until the chicken is cooked through and nicely coated with the spices.
3. Combine with Salsa and Assemble:
Stir in the salsa and let everything cook together for 1-2 minutes until heated through. Then, transfer this mixture evenly into your prepared baking dish.
4. Add Cheese and Bake:
Sprinkle the shredded cheddar and Monterey Jack cheese evenly over the top. Place the dish in the oven and bake for 15-20 minutes, or until the cheese is melted and bubbly.
5. Serve:
Remove from the oven and let cool slightly. Serve spooned into bowls or plates. Garnish with fresh cilantro and a dollop of sour cream for a fresh and creamy touch.
Can I Use Frozen Chicken in This Recipe?
Yes, you can! Just make sure to fully thaw the chicken before cooking. Thaw it overnight in the fridge or use the cold water method for quicker thawing. This helps ensure even cooking and prevents excess moisture.
Can I Substitute Different Vegetables?
Absolutely! While bell peppers and onions are classic for fajitas, you can add or swap in zucchini, mushrooms, or corn. Just adjust cooking time to soften any added veggies before assembling.
How Should I Store Leftovers?
Store leftovers in an airtight container in the fridge for up to 3 days. Reheat gently in the oven or microwave until warmed through. You might want to cover with foil when reheating in the oven to keep it moist.
Can I Make This Ahead of Time?
Yes! Prepare the chicken and veggies, assemble the casserole, then cover and refrigerate for up to 24 hours before baking. Add a few extra minutes to baking time if baking from chilled.
