Easy Weeknight Chicken Fajita Casserole: A Flavor-Packed, One-Dish Wonder

Introduction

Whether you’re juggling busy weeknights or planning a laid-back weekend dinner with friends, this easy Chicken Fajita Casserole delivers big flavors with minimal fuss.

Inspired by the sizzling aroma of homemade fajitas but reimagined as a hearty bake, Chicken Fajita Casserole brings all the fiery zest and comforting cheese pull you crave.

Picture layering charred bell peppers, tender chicken breast slices, and melty cheeses in a single dish, then broiling until golden this Chicken Fajita Casserole is perfect for casual weeknight meals, potlucks, or game-day gatherings.

Why You’ll Love This Chicken Fajita Casserole

• Effortless One-Pan Dinner: Skip juggling multiple pans—this casserole layers ingredients in one baking dish, cutting down cleanup time without sacrificing flavor.
• Customizable Heat Levels: Whether you prefer a mild weeknight meal or crave serious spice, you control the chili heat—make this Chicken Fajita Casserole as mild or fiery as you like.
• Family-Friendly Comfort: With gooey cream cheese and shredded pepper Jack, the melty cheese pull will have kids and grown-ups alike asking for seconds.
• Budget-Friendly Ingredients: Using pantry staples like bell peppers, onion, and chicken breasts keeps the cost low while delivering gourmet-style results.
• Prep in Minutes: You can slice veggies and season chicken ahead of time, then pop everything in the oven—perfect for busy evenings.
• Make-Ahead Magic: Assemble your Chicken Fajita Casserole the night before, refrigerate, and bake when you’re ready for dinner.

Ingredients for Chicken Fajita Casserole

• 3 large bell peppers, assorted colors [Tip: Choose a mix of red, yellow, and green for vibrant presentation.]
• 1 large yellow onion [Tip: Swap for white onion if you prefer a sharper bite.]
• 4 cloves garlic [Tip: Freshly minced garlic adds the brightest flavor.]
• 4 ounces pepper Jack cheese, shredded (about 1 cup) [Tip: Grate with the large holes of a box grater for a meltier texture; for extra creaminess in this Chicken Fajita Casserole, swap half the pepper Jack with Monterey Jack.]
• 4 ounces cream cheese [Tip: Cut into small cubes so it melts evenly.]
• 2 pounds boneless, skinless chicken breasts [Tip: Trim excess fat and pat dry for even browning.]
• 5 tablespoons olive oil, divided [Tip: Use extra-virgin for richer flavor.]
• 3 teaspoons store-bought or homemade taco seasoning, divided [Tip: Adjust spice level or try a salt-free blend.]
• 1/2 teaspoon kosher salt, divided [Tip: Increase by 1/2 teaspoon if you use salt-free seasoning.]
• 1/4 cup water [Tip: Helps create steam to finish cooking the chicken.]
• Serving options: fresh cilantro, flour tortillas, rice, sour cream, avocado, and/or lime wedges [Tip: Offer a few toppings so everyone can customize.]

Step-by-Step Instructions for Your Chicken Fajita Casserole

1. Slice and Prep the Veggies and Cheese
   Begin by slicing the bell peppers, onion, and garlic thinly to ensure even cooking and a balanced flavor in every bite of your Chicken Fajita Casserole. Use a sharp chef’s knife to cut 1/4-inch strips for the peppers and onion, and mince the garlic finely to release its aroma. Grate the pepper Jack cheese and cube the cream cheese so they’re ready for effortless melting later.
2. Season the Chicken
   Dry the chicken breasts thoroughly with paper towels—this step is key for a good sear. Rub each breast with 1 tablespoon of olive oil, then season evenly with 2 teaspoons of taco seasoning and 1/4 teaspoon of kosher salt. Let the chicken rest at room temperature for 5 minutes so the seasoning adheres properly.
3. Preheat the Broiler
   Adjust your oven rack about 6 inches from the broiler element and select the “low broil” setting to prevent burning. While the broiler heats up, position an empty 9×13-inch baking dish nearby for quick assembly. Preheating now means you can finish the casserole under the broiler in just minutes.
4. Cook the Chicken
   Heat a large skillet over medium heat and add 2 tablespoons of olive oil. When the oil shimmers, place the chicken breasts in a single layer and cook undisturbed for 5 to 7 minutes, or until the bottom side develops a deep golden crust. Flip the chicken, pour in 1/4 cup of water, cover with a lid, and cook for another 5 minutes until the internal temperature reaches 165°F. Remove the chicken and any pan juices to a plate to rest—this locks in juiciness.
5. Sauté the Vegetables
   Turn the heat to high and add the remaining 2 tablespoons of olive oil to the skillet. Stir in the sliced bell peppers and onion, then season with the remaining 1 teaspoon of taco seasoning and 1/4 teaspoon of kosher salt. Let the vegetables cook undisturbed for about 5 minutes so they start to char, then stir and cook for another 5 minutes until they soften and release their natural sweetness. Add the garlic and cook for 2 more minutes, stirring constantly to prevent burning, until fragrant and golden. This helps develop the deep flavors that make this Chicken Fajita Casserole so irresistible.
6. Assemble the Casserole
   Spread the sautéed vegetables evenly in the prepared baking dish, creating a colorful base. Slice the rested chicken into 1/2-inch slices and nestle them among the peppers and onions. Drizzle any collected juices from the plate over the top to keep everything juicy.
7. Top with Cheeses
   Sprinkle the shredded pepper Jack cheese evenly across the casserole, then scatter the cream cheese cubes on top. The contrasting textures of gooey shredded cheese and pockets of melty cream cheese create a decadent topping that’s both creamy and flavorful.
8. Broil and Serve
   Slide the baking dish under the broiler for about 5 minutes, watching closely so the cheeses melt completely and turn golden brown. Once bubbly and lightly browned, remove the casserole and let it rest for 2 minutes before serving. Garnish with fresh cilantro, and offer sides like warm flour tortillas, fluffy rice, sour cream, avocado slices, and lime wedges for a build-your-own feast.

Recipe Variations for Chicken Fajita Casserole

• Vegetarian Twist: Replace the chicken with firm tofu or a can of drained black beans for a meat-free version that still packs protein and flavor.
• Low-Carb Option: Omit the tortillas or rice and serve the casserole over a bed of cauliflower rice for a lighter, keto-friendly meal.
• Spicy Upgrade: Add sliced jalapeños or a dash of chipotle powder to the vegetable mix for an extra kick.
• Creamy Southwest: Stir in a handful of corn kernels and a spoonful of salsa verde before baking for an added Southwestern flair.

Serving Suggestions for Chicken Fajita Casserole

Serve individual portions on warm flour tortillas for DIY chicken fajita wraps let everyone add cilantro, sour cream, or avocado to taste. For a heartier meal, pair with a side of cilantro-lime rice or Mexican-style street corn salad to balance the spiciness with cool, bright flavors. A crisp green salad with a lime-vinaigrette or grilled veggies complements the rich cheeses and smoky peppers beautifully. For beverage pairings, try a refreshing agua fresca, like watermelon or cucumber-lime, to round out the feast.

Storage & Leftover Tips

To store leftovers, let the casserole cool completely, then transfer to an airtight container and refrigerate for up to 4 days. For longer storage, freeze portions in freezer-safe bags or containers for up to 1 month; thaw overnight in the refrigerator before reheating. To reheat, place in a 350°F oven for 20 to 25 minutes until warmed through and the cheese is bubbly again. Next-day, repurpose slices into breakfast quesadillas or layer them in a burrito for a quick grab-and-go meal.

Conclusion & Call to Action

Whether you’re feeding a crowd or just craving something flavorful, this casserole checks all the boxes: easy prep, hands-off cooking, and a crowd-pleasing cheese pull. It’s the kind of recipe that becomes a regular in your dinner rotation and a surefire way to add a little fiesta to any weeknight.

I’d love to hear how your version turns out drop a comment below with your favorite toppings or any creative twists you tried, and don’t forget to share this recipe on social media if you loved it! If you liked this, try my French Onion Frittata !

Print Recipe

Chicken Fajita Casserole

A delicious and easy casserole featuring chicken, bell peppers, and cheese, perfect for weeknight dinners.

Prep Time10 minutes mins

Cook Time30 minutes mins

Total Time40 minutes mins

Servings: 6

Ingredients

Main Ingredients

• 3 large bell peppers, assorted colors
• 1 large yellow onion
• 4 cloves garlic
• 4 ounces pepper Jack cheese, shredded (about 1 cup)
• 4 ounces cream cheese
• 2 pounds boneless, skinless chicken breasts
• 5 tablespoons olive oil, divided
• 3 teaspoons taco seasoning, divided store-bought or homemade
• 1/2 teaspoon kosher salt, divided
• 1/4 cup water

Instructions

Preparation Instructions

• Begin by slicing the bell peppers, onion, and garlic thinly. Grate the pepper Jack cheese using the large holes of a box grater, which gives about 1 cup. Cut the cream cheese into small cubes.
• Dry the chicken breasts with paper towels. Rub them with 1 tablespoon of olive oil, and season with 2 teaspoons of taco seasoning and 1/4 teaspoon of kosher salt.
• Set your oven rack about 6 inches from the broiler and preheat the oven to broil on low.
• In a large skillet over medium heat, add 2 tablespoons of olive oil and heat until shimmering. Place the chicken breasts in the skillet in a single layer and let them cook without moving for 5 to 7 minutes until the bottoms are browned and lift easily from the pan. Flip the chicken, pour in 1/4 cup of water, cover, and cook for an additional 5 minutes until the chicken is fully cooked. Remove the chicken and juices from the pan and place them on a plate.
• Raise the heat to high. Add the remaining 2 tablespoons of olive oil, sliced bell peppers, and onion to the skillet. Season with the remaining 1/4 teaspoon kosher salt and 1 teaspoon taco seasoning. Stir well and let cook undisturbed for 5 to 7 minutes until they start to char. Stir again, then cook for about 5 minutes until slightly softened. Add in the garlic and cook until fragrant, about 2 minutes.
• Spread the vegetables evenly in a 9x13-inch baking dish. Cut the chicken into 1/2-inch slices and place them among the peppers and onions in the baking dish. Pour any juices from the plate over the dish. Top with the grated pepper Jack cheese and scatter the cream cheese cubes on top.
• Broil the casserole for about 5 minutes, or until the cheeses are melted and golden. If desired, garnish with cilantro and serve with tortillas, rice, and other toppings.

Notes

Prep time is 10 minutes and cook time is 30 minutes, making 6 to 8 servings. If using salt-free taco seasoning, add 1/2 teaspoon kosher salt while seasoning the chicken, and an additional 1/2 teaspoon for the vegetables. This casserole can be stored in the fridge in an airtight container for up to 4 days or frozen for up to 1 month. To reheat, thaw it overnight in the refrigerator and heat in a 350°F oven for 20 to 25 minutes until warmed through.