Chicken Fajita Casserole

Introduction

If you love sizzling skillet fajitas but wish they were as easy as a one-pan bake, you’re going to fall head-over-heels for this Chicken Fajita Casserole. It combines all the bold, zesty flavors of classic chicken fajitas—think juicy seasoned chicken, sweet bell peppers, and sharp onions—tucked under a blanket of melted cheese and baked to bubbly perfection. It’s the perfect fusion of Tex-Mex flavor and cozy casserole comfort.

Fajitas date back to the ranch lands of South and West Texas where Mexican cowboys, known as vaqueros, were given tougher cuts of meat as partial payment. Skirt steak was the original fajita meat, cooked over open flame and served in tortillas. Over the years, fajitas have been reinvented using chicken, shrimp, and vegetables, and served in everything from tacos to rice bowls—and now, casseroles!

What sets this particular version apart? This Chicken Fajita Casserole transforms fajitas into an ultra-convenient oven-baked dish with minimal clean-up and maximum flavor. It’s hearty, cheesy, and totally customizable—perfect for weeknight dinners or casual entertaining. Plus, it’s naturally low-carb and can easily be made gluten-free. Let’s dive in!

Ingredients

For the Chicken and Marinade

• 1.5 lbs (680 g) boneless, skinless chicken breasts or thighs, sliced into thin strips
• 2 tablespoons olive oil (30 ml)
• 1 tablespoon lime juice (15 ml)
• 2 teaspoons chili powder (5 g)
• 1 teaspoon smoked paprika (2 g)
• 1 teaspoon ground cumin (2 g)
• 1/2 teaspoon garlic powder (1 g)
• 1/2 teaspoon onion powder (1 g)
• 1/2 teaspoon salt (2.5 g)
• 1/4 teaspoon ground black pepper (1 g)

For the Casserole Assembly

• 1 tablespoon olive oil (15 ml)
• 1 large red bell pepper, sliced
• 1 large green bell pepper, sliced
• 1 medium yellow onion, sliced
• 1 cup sour cream (240 ml)
• 1/2 cup cream cheese, softened (120 g)
• 1 1/2 cups shredded cheddar cheese, divided (170 g)
• 1 cup shredded Monterey Jack or Pepper Jack cheese (113 g)
• 1/4 cup chopped cilantro (optional – for garnish)
• Lime wedges, for serving

Instructions

1. Marinate the chicken: In a bowl or zip-top bag, combine olive oil, lime juice, chili powder, paprika, cumin, garlic powder, onion powder, salt, and pepper. Add the sliced chicken and toss well to coat. Cover and refrigerate for at least 30 minutes (or up to 8 hours for deeper flavor).
2. Preheat the oven: Set your oven to 375°F (190°C) and lightly grease a 9×13-inch (23×33 cm) baking dish.
3. Cook the chicken: Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the marinated chicken strips and sauté for about 5-6 minutes, until mostly cooked through and lightly golden. Remove from pan and set aside.
4. Sauté the veggies: In the same skillet, add the sliced bell peppers and onions. Cook for 4-5 minutes, until tender and slightly caramelized. Season lightly with salt and pepper.
5. Mix the creamy base: In a large mixing bowl, combine sour cream and softened cream cheese. Stir until smooth and no lumps remain.
6. Add the components: To the sour cream mixture, fold in the cooked chicken, sautéed peppers and onions, and half of the shredded cheddar and Monterey Jack cheese. Mix gently to combine.
7. Assemble the casserole: Pour the mixture into the prepared baking dish and smooth the top evenly using a spatula.
8. Top with cheese: Sprinkle the remaining cheddar and Monterey Jack cheeses evenly over the top of the casserole.
9. Bake: Place the dish in the preheated oven and bake for 20-25 minutes, or until the cheese is melted and bubbly around the edges.
10. Broil (optional): For a golden-brown cheesy top, broil for an additional 2-3 minutes. Keep a close eye to avoid burning.
11. Garnish and serve: Remove from the oven and let rest for 5-10 minutes. Garnish with freshly chopped cilantro and serve with lime wedges.
12. Serving suggestions: Enjoy it as a main course with rice, tortillas, or on its own for a low-carb option.
13. Tip: If you want to add some heat, toss in sliced jalapeños or a pinch of cayenne when sautéing the vegetables.
14. Tip: Want to make it even more filling? Add cooked rice or black beans to the mixture before baking.
15. Make it your own: Use rotisserie chicken for an ultra-quick prep or switch up the cheese based on preference!

Recipe Information

• Prep Time: 30 minutes (including marinating time)
• Cook Time: 30 minutes
• Total Time: 60 minutes
• Serving Size: 1 generous scoop (approx. 1/6 of casserole)
• Yield: 6 servings
• Difficulty: Easy to Medium

Tips & Variations

• Use pre-cooked chicken: Swap the raw chicken with shredded rotisserie chicken to save time—just mix it directly into the casserole base.
• Low-carb option: Skip the tortillas and serve with cauliflower rice or a green salad for a keto-friendly meal.
• Add grains or beans: Make it heartier by stirring in 1 cup (200 g) of cooked rice, quinoa, or drained black beans.
• Make it ahead: Prepare the casserole up to Step 8, cover, and refrigerate for up to 2 days. Bake fresh when ready to eat.
• Storage: Store leftovers in an airtight container in the refrigerator for up to 4 days.
• Reheating: Reheat individual portions in the microwave for 1-2 minutes, or warm the full casserole in a 350°F (175°C) oven until hot throughout (about 15-20 minutes).

Nutritional Information

Per Serving (approximate)

• Calories: 410
• Protein: 36g
• Carbohydrates: 9g
• Fat: 26g
• Fiber: 2g

Conclusion

This Chicken Fajita Casserole brings all the flair of your favorite skillet fajitas into a comforting, cheesy, oven-baked dish that’s perfect for any night of the week. Whether you’re feeding your family, meal prepping for the week, or hosting a casual dinner night, this Tex-Mex favorite is bound to wow anyone lucky enough to dig in.

Try pairing it with warm tortillas, a scoop of Spanish rice, or a crisp green salad with lime vinaigrette. Love it? Let us know in the comments below! Share it on social media, tag us, and don’t forget to rate the recipe. How did you make it your own? We’d love to hear!