Name: Cheesy Fajita Chicken Casserole Recipe
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: Mexican
Ingredients: 1 ½ pounds chicken breasts skinless and boneless; 2 tablespoons fajita seasoning; 1 tablespoon vegetable oil; 2 medium bell peppers cut into strips; 1 medium yellow onion sliced; 1 ½ cups shredded cheese; fresh chopped cilantro for garnish

This Cheesy Fajita Chicken Casserole Recipe is a total game changer when you want something packed with flavor but still easy enough for a busy weeknight. You get juicy chicken, melty cheese, and those classic fajita spices all baked in one dish – trust me, you’re going to love it!

A white plate on a white marbled surface holds one main piece of cooked meat topped with melted yellow cheese, showing a slightly crispy texture at the edges. Red and green pepper strips lie on top of and slightly beside the meat, adding bright color. A small green herb leaf decorates the center. The melted cheese covers the meat and peppers, stretching down the sides, creating a warm and rich look. A silver fork is placed near the edge of the plate. Photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Cheesy Fajita Chicken Casserole Recipe
Top Tip
How to Serve Cheesy Fajita Chicken Casserole Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Cheesy Fajita Chicken Casserole Recipe

Why You'll Love This Recipe

Honestly, this casserole hits all the right notes for me. It’s flavorful without being fussy, cheesy but balanced with fresh veggies, and really speedy – perfect for those nights when you want something comforting but don’t want to slave over the stove.

Simple prep: You only need one baking dish and a handful of ingredients for a fuss-free meal.
Rich flavor without extra effort: The fajita seasoning does all the heavy lifting for that smoky, spicy kick.
Versatile and customizable: You can easily swap veggies or add extras like cooked pasta to suit your taste.
Family-friendly and wholesome: Packed with protein and veggies, it’s a crowd-pleaser that feels just a little bit special.

Ingredients & Why They Work

Every ingredient in this Cheesy Fajita Chicken Casserole Recipe plays a role. The chicken stays juicy and tender, the seasoning brings punch, and the veggies add freshness plus a pop of color. Here’s a bit about why each works so well together (and a tip or two for shopping):

Flat lay of skinless boneless chicken breasts, two medium bell peppers cut into strips—one red, one green, one medium yellow onion sliced, a small pile of shredded cheese, a small white bowl of vegetable oil, a small white bowl of fajita seasoning powder, fresh chopped cilantro leaves scattered loosely, all arranged symmetrically on simple white ceramic bowls and plates, placed on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p m7354615311229779997

Chicken breasts: Lean and mild, perfect for soaking up fajita seasoning and juicing up under the cheese.
Fajita seasoning: A spice blend that sparks warmth and zest, no extra spices needed.
Vegetable oil: Helps coat the chicken so the seasoning sticks and everything roasts beautifully.
Bell peppers: Their crunch and sweetness balance the savory chicken and spices perfectly.
Yellow onion: Adds a subtle sweetness and depth when baked alongside the chicken.
Shredded cheese: Melted goodness that binds everything and adds creaminess. I like a sharp cheddar or a Mexican blend for depth.
Fresh cilantro: Brightens the finished dish with fresh herbal notes and looks pretty too!

📝

Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

I love tweaking this Cheesy Fajita Chicken Casserole Recipe based on what’s on hand or my mood. It’s a forgiving recipe, so go ahead and experiment—you might find a new favorite twist.

Variation: One time, I swapped bell peppers for poblano and poblano chiles for a bit more heat and earthiness, and it turned out fantastic!
Low-calorie change: Skipping the cheese and topping with a Parmesan-panko crust before baking keeps things crispy but lighter.
Adding pasta: Mixing in some cooked pasta before baking makes it a heartier, comforting casserole perfect for cold weather.

Step-by-Step: How I Make Cheesy Fajita Chicken Casserole Recipe

A white baking dish filled with a colorful baked casserole, showing layers of melted bright orange cheese covering sliced red and green bell peppers and other vegetables. The cheese is bubbly and slightly browned in some parts, giving a smooth, rich texture on top. Green cilantro leaves are scattered across the top, adding a fresh touch. The casserole looks thick and hearty, with the veggies mixed evenly under the cheese. The dish rests on a white marbled surface. photo taken with an iphone --ar 2:3 --v 7

Step 1: Season and oil the chicken

First things first: preheat your oven to 400°F (200°C). I pour a bit of vegetable oil right onto the chicken breasts in the baking dish and sprinkle the fajita seasoning all over. To get the most flavor, I like to rub it in with my hands—don’t be shy! This way the seasoning sticks well for that tasty crust.

Step 2: Layer the veggies and cheese

Next, pile on the sliced bell peppers and onions over the chicken. I add just a bit more fajita seasoning on top before sprinkling a generous handful of shredded cheese. The cheese melts over everything, tying it all together.

Step 3: Bake and check doneness

Pop the uncovered baking dish into the oven for about 25–30 minutes. A meat thermometer is your best friend here—when the chicken reaches 165°F (74°C) inside, you’re golden. The cheese should be bubbly and lightly browned on top.

Step 4: Garnish and serve it up

Once out of the oven, sprinkle freshly chopped cilantro on top for brightness, and serve immediately. It goes wonderfully with a scoop of rice or even a side salad if you want to keep it light.

Top Tip

I've made this Cheesy Fajita Chicken Casserole Recipe countless times, so here are a few nuggets to make sure yours turns out just perfect every time.

Season generously: Don’t be afraid to rub in the fajita seasoning really well so every bite has that smoky, spicy flavor.
Use a meat thermometer: This simple tool takes the guesswork out of ensuring chicken is cooked safely without drying out.
Slice veggies evenly: Uniform slices mean they’ll roast evenly alongside the chicken and deliver perfect texture.
Don’t cover the casserole: Leaving it uncovered helps the cheese get golden and prevents that soggy top.

How to Serve Cheesy Fajita Chicken Casserole Recipe

A white rectangular baking dish holds four pieces of seasoned cooked chicken laid side by side in one layer, showing a golden brown color with a slightly crispy texture and light spices sprinkled on top. The dish sits on a white marbled surface. Photo taken with an iphone --ar 2:3 --v 7

Garnishes

I always add a handful of fresh chopped cilantro after baking—it brightens the whole dish. Sometimes I’ll add a dollop of sour cream or some sliced avocado on the side to bring creamy coolness against the spice. If you’re feeling adventurous, a squeeze of lime juice on top really wakes up the flavors.

Side Dishes

I like pairing this casserole with garlic butter pasta or Mexican rice for a full-on feast. When I want to keep it lighter, cauliflower rice is my go-to—it soaks up the juices nicely without extra carbs. A simple green salad with a citrusy dressing also balances the richness perfectly.

Creative Ways to Present

For a casual dinner party, I’ve served this casserole in individual ramekins topped with a sprinkle of fresh jalapeño slices and an extra pinch of cheese broiled just before serving. It looks impressive but takes almost no extra effort. For family dinners, I sometimes add black beans and corn into the mix for a southwestern twist.

Make Ahead and Storage

Storing Leftovers

I store leftovers in airtight containers in the fridge and they keep well for 3–4 days. The flavors actually deepen overnight! Just be sure to let it cool down a bit before refrigerating to keep the texture nice.

Freezing

This recipe freezes beautifully. I portion out individual servings in freezer-safe containers, and when I’m ready to eat, I thaw overnight in the fridge. The texture and flavor stay surprisingly great after freezing.

Reheating

To reheat, I prefer the oven at 350°F (175°C) for 15-20 minutes to keep that cheesy top melty and the chicken juicy. If you’re short on time, the microwave works fine—just cover loosely to avoid drying out.

Frequently Asked Questions:

Can I use chicken thighs instead of breasts?

Absolutely! Chicken thighs are juicier and more forgiving if you’re worried about dryness. Just adjust the cooking time slightly and check for doneness.

What if I don’t have fajita seasoning?

No worries! You can make your own by mixing chili powder, cumin, paprika, garlic powder, onion powder, and a pinch of salt and pepper. It won’t take long and tastes fresh.

Can I make this recipe gluten-free?

Definitely. Just make sure your fajita seasoning doesn’t contain any gluten additives. Using corn-based rice or cauliflower rice as a side also keeps it gluten-free.

How do I avoid soggy veggies in the casserole?

Slice bell peppers and onions evenly and don’t cover the casserole while baking. Also, avoid overcrowding the baking dish so veggies roast nicely rather than steam.

Final Thoughts

If you’re looking for a recipe that’s simple to toss together but still feels like a winner at the dinner table, you’ve got to try this Cheesy Fajita Chicken Casserole Recipe. It’s one of those dishes that feels like a hug in food form—comforting, flavorful, and always satisfying. Honestly, I keep coming back to it whenever I want all the best fajita flavors with zero drama. Give it a go—I can’t wait to hear how you make it your own!