This Cheesy Baked Chicken Fajita Casserole is the ultimate low-effort, high-flavor dinner that brings the sizzling taste of fajitas straight to your oven. Tender chicken breasts are seasoned with bold spices, topped with crisp peppers and onions, and smothered in melted cheese for a one-pan meal that is both healthy and indulgent.
Perfect for low-carb diets or anyone who loves a quick cleanup, this 30-minute meal delivers maximum satisfaction with minimal work.
Recipe Details
- Flavor Profile: A classic Tex-Mex combination of savory fajita spices, sweet roasted peppers and onions, and rich, bubbly cheese.
- Texture: Juicy baked chicken is blanketed by tender-crisp vegetables and a gooey layer of melted cheese.
- Time: 5 minutes prep, 30 minutes bake time.
- Difficulty: Very Easy. It is a simple “dump and bake” method.
What You’ll Need
To make this recipe, you will need a 9×13-inch baking dish to hold the chicken and vegetables in a single layer. A sharp knife is essential for slicing the peppers and onions. The ingredients are minimal: boneless skinless chicken breasts, fresh produce, shredded cheese, and your favorite fajita seasoning blend (homemade or store-bought).
Ingredient Notes
- Chicken Breasts – Use 1 ½ pounds of boneless, skinless chicken breasts. You can leave them whole if they are thin, or pound them to an even thickness so they cook through at the same rate as the veggies.
- Fajita Seasoning – This all-in-one spice blend provides the signature cumin, chili, and garlic flavors.
- Bell Peppers – Use 2 medium bell peppers. A mix of colors (like red and green) adds sweetness and visual appeal. Slice them into strips.
- Yellow Onion – Sliced onion adds savory depth and sweetness as it roasts.
- Vegetable Oil – A tablespoon of oil helps the seasoning stick to the chicken and keeps it moist during baking.
- Cheese – Shredded cheese (Cheddar, Monterey Jack, or a Mexican blend) melts over everything to tie the dish together.
- Cilantro – Fresh chopped cilantro adds a burst of color and herbal freshness to finish the dish.
Add-ins and Substitutions
- Protein – Boneless skinless chicken thighs are a juicy alternative to breasts.
- Spice – If you like heat, add sliced jalapeños or a pinch of cayenne pepper to the seasoning mix.
- Vegetables – Zucchini slices or mushrooms can be added to the pepper mixture for extra nutrition.
- Cheese – Pepper Jack cheese is a great option for a spicy kick.
How to Make Cheesy Baked Chicken Fajita Casserole
- Prep: Preheat oven to 400°F (200°C).
- Season Chicken: Place the chicken breasts directly into the baking dish. Drizzle with the vegetable oil and sprinkle generously with the fajita seasoning. Rub the seasoning and oil all over the chicken with your hands to ensure it is well distributed and coated.
- Layer Veggies: Top the seasoned chicken with the sliced bell peppers and onion. Sprinkle a little bit more fajita seasoning over the vegetables if desired.
- Add Cheese: Top the entire dish evenly with the shredded cheese.
- Bake: Bake the chicken casserole in the oven uncovered for 25-30 minutes, or until the chicken is cooked through (internal temperature of 165°F) and the cheese is bubbly and golden.
- Serve: Serve immediately, garnished with fresh cilantro leaves if desired.
Pro Tip: If your chicken breasts are very thick, slice them in half horizontally to create thinner cutlets. This ensures they cook through in 25 minutes without drying out, matching the cooking time of the peppers perfectly.
Recipe Tips
- Don’t Overcrowd: Use a baking dish large enough (like 9×13) so the chicken isn’t piled on top of each other. This helps it bake evenly rather than steam.
- Cheese Timing: If you prefer your cheese less browned, you can bake the chicken and veggies for 20 minutes, then add the cheese for the final 5-10 minutes.
- Resting: Let the casserole sit for 5 minutes after baking. This allows the juices to redistribute in the chicken so it stays moist when you cut into it.
FAQs
- Is this keto? Yes! This recipe is naturally low-carb and high-protein, making it perfect for keto and gluten-free diets (check your seasoning packet ingredients).
- Can I use taco seasoning? Yes, taco seasoning is very similar and works as a great substitute if you don’t have fajita seasoning.
- How do I store leftovers? Store leftovers in an airtight container in the refrigerator for up to 3 days.
Serving Suggestions
- Tortillas: Serve with warm flour or corn tortillas for a classic fajita taco night.
- Rice: Spoon the chicken and juices over Mexican rice or cilantro lime rice.
- Salad: For a lighter meal, serve the chicken and peppers over a bed of crisp romaine lettuce with avocado and salsa.
Make This Recipe in Advance
- Prep: You can slice the peppers and onions and trim the chicken the night before. Store them in separate containers in the fridge.
- Assembly: Assemble the entire casserole (up to the baking step) in the morning and keep it covered in the fridge. Bake it fresh for dinner (add 5-10 minutes if cooking from cold).
Cheesy Baked Chicken Fajita Casserole
- Total Time: 35 minutes
- Yield: 4-6 Servings 1x
Description
This Cheesy Baked Chicken Fajita Casserole is the ultimate low-effort, high-flavor dinner that brings the sizzling taste of fajitas straight to your oven. Tender chicken breasts are seasoned with bold spices, topped with crisp peppers and onions, and smothered in melted cheese for a one-pan meal that is both healthy and indulgent. Perfect for low-carb diets or anyone who loves a quick cleanup, this 30-minute meal delivers maximum satisfaction with minimal work.
Ingredients
- 1 ½ lbs (680g) boneless, skinless chicken breasts
- 2 tablespoons fajita seasoning (store-bought or homemade)
- 1 tablespoon vegetable oil (or olive oil)
- 2 medium bell peppers (any color), cut into strips
- 1 medium yellow onion, sliced into strips
- 1 ½ cups shredded cheese (Cheddar, Monterey Jack, or Mexican Blend)
- Fresh chopped cilantro, for garnish
Instructions
Prep
Preheat your oven to 400°F (200°C). Spray a 9×13-inch baking dish with non-stick spray.
Season Chicken
Place the chicken breasts directly into the baking dish.
Coat
Drizzle with the vegetable oil and sprinkle generously with the fajita seasoning. Rub the oil and spices all over the chicken with your hands to ensure it is thoroughly coated.
Layer Veggies
Top the seasoned chicken with the sliced bell peppers and onions. Tip: You can sprinkle a little extra pinch of seasoning over the vegetables if you like bold flavor.
Add Cheese
Sprinkle the shredded cheese evenly over the top of the vegetables and chicken.
Bake
Bake uncovered for 25–30 minutes. Check: Cook until the cheese is bubbly and golden, and the chicken reaches an internal temperature of 165°F (74°C).
Serve
Let the casserole rest for 5 minutes (to keep the juices inside the chicken). Garnish with fresh cilantro and serve immediately.
Notes
Chicken Thickness: If your chicken breasts are very thick, slice them in half horizontally (butterfly style) to create thinner cutlets. This ensures they cook through in 25 minutes without drying out, matching the cooking time of the peppers perfectly.
Cheese Timing: If you prefer your cheese melted but not browned, bake the chicken and veggies for 20 minutes first, then add the cheese for the final 5–10 minutes of baking.
Diet Friendly: This recipe is naturally Keto and Low-Carb. Just ensure your fajita seasoning packet doesn’t contain added sugar or cornstarch fillers.
Substitutions: No fajita seasoning? Taco seasoning works as a great substitute. You can also swap chicken breasts for boneless skinless thighs for a juicier bite.
- Prep Time: 5 minutes
- Cook Time: 30 minutes
- Category: Dinner / Casserole
- Method: Baked
- Cuisine: Tex-Mex
Nutrition
- Serving Size: 1/6 of Recipe
- Calories: 320
- Sugar: 3g
- Sodium: 480mg
- Fat: 14g
- Saturated Fat: 7g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 6g
- Fiber: 1g
- Protein: 38g
- Cholesterol: 105mg
Keywords: chicken fajita casserole, keto chicken dinner, low carb casserole, baked fajitas, sheet pan chicken, healthy mexican recipes, gluten free dinner
