Chicken Fajita Casserole Recipe

If you love the smoky, spicy, and comforting flavors of Mexican cuisine but want a simple one-dish meal to brighten your table, this Chicken Fajita Casserole Recipe is an absolute must-try. It brilliantly combines tender chicken, vibrant bell peppers and onions, creamy cheese, and that unbeatable fajita seasoning all baked into a golden, bubbly casserole. Whether you’re feeding family or friends, this dish is a crowd-pleaser that’s easy enough to whip up on a weeknight yet special enough to impress.

Ingredients You’ll Need

Each ingredient in this Chicken Fajita Casserole Recipe plays a crucial role in layering flavors and textures that make every bite irresistible. From fresh veggies adding crunch and color to spices delivering that signature kick, every element is thoughtfully chosen and simple to find.

• 1 Tablespoon olive oil or avocado oil: Perfect for sautéing and adding a subtle richness to the veggies.
• 1 teaspoon minced garlic (about 2 cloves): A punch of aromatic depth that brings the whole dish together.
• 1 bell pepper, thinly sliced: Adds sweet crunch and vibrant color.
• 1 small onion, thinly sliced: Provides sweetness and layers of flavor when caramelized.
• 1 large sweet potato, peeled and diced small: Brings natural sweetness and heartiness, or swap with cooked rice for a different texture.
• 1 – 1 ½ teaspoons chili powder: I love using chipotle chili powder here for a smoky, spicy note.
• 1 teaspoon ground cumin: Gives that warm earthiness essential to fajitas.
• ¼ to ½ teaspoon paprika or smoked paprika: Adds smokiness and a beautiful color.
• 1 teaspoon kosher salt: Enhances all the flavors perfectly.
• ½ teaspoon black pepper: For a gentle heat and balance.
• 2 Tablespoons olive oil or dairy-free butter: Helps build the creamy sauce base with richness.
• 2 Tablespoons arrowroot starch (or 1 Tablespoon cornstarch): Mixed with water to thicken the sauce for the perfect silky texture.
• 1 (10 oz) can diced tomatoes with green chiles (undrained): Adds juiciness and a subtle spicy kick.
• ¾ cup unsweetened non-dairy milk or coconut milk, or 1 cup chicken broth: Makes the sauce creamy or lighter, depending on your preference.
• Optional splash of lime juice: Brightens the sauce with a little tang.
• 2 cups shredded or diced cooked chicken: Rotisserie or grilled chicken works wonderfully—just avoid overly seasoned to let the spices shine.
• 2 cups shredded sharp cheddar cheese, divided: Melty, flavorful, and essential for that gooey topping.
• 4 ounces (about 3 cups) gluten-free tortilla chips: Adds crunch and fajita authenticity.
• Optional toppings: Think shredded lettuce, cilantro, avocado, sour cream, salsa, pico de gallo – all your favorites for garnish.

How to Make Chicken Fajita Casserole Recipe

Step 1: Sauté the Veggies

Start by heating oil in a large oven-proof skillet over medium heat. Toss in the sliced onion and bell pepper, cooking them gently for a couple of minutes until they soften and release their sweetness. Then add the minced garlic and stir quickly, making sure it doesn’t burn but infuses the mix with that irresistible aroma.

Step 2: Cook the Sweet Potato

Next, stir in the diced sweet potato. Cover the skillet and let the potatoes cook undisturbed for 4–5 minutes to begin softening. Then remove the lid and give everything a good stir. Continue cooking for another 3–5 minutes until the sweet potatoes are fork-tender with a lovely tender bite. Add a bit more oil if things start to stick to the pan because you want those veggies to cook evenly and develop flavor without burning.

Step 3: Season the Vegetables

Sprinkle in chili powder, cumin, paprika, kosher salt, and black pepper. These spices bring the authentic fajita flavor base you’re craving. Once mixed thoroughly, transfer the veggies to a bowl and set them aside as you start the sauce.

Step 4: Make the Creamy Sauce

In the same skillet, melt the butter or heat olive oil over medium heat. Pour in your milk or chicken broth and gently bring the liquid to a simmer while scraping up those delicious browned bits stuck to the pan – that’s pure flavor magic right there! Stir in the canned diced tomatoes with green chiles, undrained. Then slowly whisk in your arrowroot or cornstarch slurry, a bit at a time, until the sauce thickens to a creamy consistency, which should take about 3–5 minutes. If you’re using milk, add a splash of lime juice to brighten the flavors.

Step 5: Combine Chicken, Veggies, and Cheese

Stir in the shredded chicken, half of the sautéed veggies, and 1 cup of shredded cheese into the creamy sauce. Mix everything until it’s well combined and evenly coated. This step ensures every bite will have that luscious, cheesy fajita goodness!

Step 6: Assemble the Casserole

Spread the remaining veggies on top of the chicken mixture. Now scatter the tortilla chips over the top for that exciting crunch. Save a handful of chips to sprinkle in the last few minutes of baking to maximize that crisp texture. Finally, top with the last cup of shredded cheese for a golden, bubbly finish.

Step 7: Bake to Perfection

Bake your Chicken Fajita Casserole Recipe in a preheated 375°F oven for 15–20 minutes or until it’s piping hot and the edges turn beautifully golden. For an extra touch of toasty cheese, switch to broil for 1 minute at the end, but watch carefully so it doesn’t burn.

How to Serve Chicken Fajita Casserole Recipe

Garnishes

Topping this casserole with fresh and colorful garnishes takes it to the next level. I love adding luscious slices of creamy avocado or a dollop of guacamole for smoothness, crisp shredded lettuce for freshness, freshly chopped cilantro for a herbal note, sour cream for tangy creaminess, and a spoonful of salsa or pico de gallo for a pop of brightness. These not only enhance flavor but bring a festive look to your plate.

Side Dishes

You can serve this casserole with simple sides that complement the bold flavors. A fresh green salad tossed with lime vinaigrette or a side of black beans makes for a well-rounded meal. If you prefer something warm, Mexican street corn or a pot of cumin-lime rice pairs beautifully without overshadowing the star dish.

Creative Ways to Present

Feeling fancy? Serve the Chicken Fajita Casserole Recipe as individual portions in small ramekins for a pretty presentation. Alternatively, scoop it into warm corn tortillas for a deconstructed fajita-style feast, or pile it onto crunchy tostada shells for a fun twist. It’s so versatile you can reinvent the way you enjoy it every time!

Make Ahead and Storage

Storing Leftovers

Once cooled, transfer leftovers to an airtight container and store in the refrigerator. It will stay fresh for 3 to 4 days, making it a perfect option for quick lunches or dinners during busy days. The flavors often deepen overnight too!

Freezing

This Chicken Fajita Casserole Recipe freezes wonderfully. To freeze, portion into freezer-safe containers and keep for up to 2 months. When ready to enjoy, thaw overnight in the fridge before reheating, preserving that fresh-cooked taste.

Reheating

Reheat leftovers gently in the oven at 350°F until hot and bubbly—this helps retain the crisp topping. Alternatively, microwave individual servings if you’re in a hurry, but it may soften the chips. You can always add fresh tortilla chips on top after reheating for that satisfying crunch again.

FAQs

Can I use regular potatoes instead of sweet potatoes in this Chicken Fajita Casserole Recipe?

Yes, regular potatoes can be substituted, but sweet potatoes add a natural sweetness and creamy texture that balances the spices beautifully. If using regular potatoes, choose a waxy variety and dice small for even cooking.

Is it possible to make this casserole dairy-free?

Absolutely! Use dairy-free butter alternatives and opt for sharp dairy-free cheddar cheese. Also, choose unsweetened non-dairy milk like coconut or almond milk for the sauce. The recipe works beautifully without any dairy.

Can I prepare this casserole ahead of time?

Definitely! You can prepare the entire casserole up to the baking step, cover, and refrigerate for up to 24 hours before baking. This makes it a fantastic meal prep option or a dish to assemble before guests arrive.

What can I use instead of chicken if I want a vegetarian version?

For a vegetarian twist, swap the chicken for cooked beans like black beans or pinto beans, or try cooked tofu cubes seasoned with fajita spices. The casserole will still be hearty and flavorful!

How spicy is this dish?

The heat level is moderate and adjustable—chipotle chili powder gives smoky warmth without overpowering, but you can dial it down or up depending on your taste by varying the chili powder amount or adding fresh jalapeños.

Final Thoughts

This Chicken Fajita Casserole Recipe has quickly become one of my favorite go-to meals when I crave comforting, bold flavors all in one cozy dish. It’s approachable, packed with vibrant ingredients, and makes for an impressive yet easy dinner that everyone will adore. I can’t wait for you to try it and see how quickly it becomes a beloved staple in your kitchen too!

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