Name: Mexican Chicken Fajita Casserole Recipe
Prep time: 15 min
Cook time: PT-496372H48M55S
Total time: PT-496372H48M55S
Cuisine: Mexican
Ingredients: 1 (16-ounce) jar thick and chunky salsa; 1 (15-ounce) can black beans, rinsed and drained; 1 (14.5-ounce) can fat-free, reduced-sodium chicken broth; 1 cup uncooked quinoa, rinsed if needed; 1 red pepper, cut into strips (about 1½ cups); 1 green pepper, cut into strips (about 1½ cups); ½ large sweet onion, cut into strips (about 1¾ to 2 cups); 1 pound boneless, skinless chicken breasts or chicken tenders, cut into strips; 1 tablespoon olive oil; 3 teaspoons chili powder; 2½ teaspoons ground cumin; 2 teaspoons garlic powder; 1½ teaspoons kosher salt; Shredded reduced-fat cheese; Shredded lettuce; Reduced-fat sour cream; Avocados or guacamole; Chopped cilantro or green onions; Hot sauce such as Tapatío

Jump to Recipe· 3.9 from 61 reviews

If you are craving a vibrant, hearty, and comforting dish that brings the fiesta right to your dinner table, this Mexican Chicken Fajita Casserole Recipe is exactly what you need. It masterfully combines tender chicken, colorful peppers, and fluffy quinoa all mingled in a tangy, mildly spicy salsa base, baked to bubbly perfection. This casserole embodies all the irresistible flavors of fajitas without the fuss of individual skillet cooking—perfect for busy weeknights or feeding a crowd with ease.

Ingredients You’ll Need

A wooden board on a white marbled surface holds several ingredients: two raw chicken pieces placed on white paper at the bottom left, a red bell pepper just above the chicken, and a green bell pepper to the right of an onion positioned in the center. To the top right of the onion is a white bowl filled with black beans. Above the board, a white bowl with light-colored quinoa and a wooden spoon inside sits to the left. Below the quinoa bowl and left of the chicken, there is a small white dish divided into four parts with different spices and salt. At the bottom right corner, a white bowl filled with chunky red salsa, having a spoon in it, is placed. The background and surface are white marbled. Photo taken with an iphone --ar 4:5 --v 7

Gathering simple, wholesome ingredients is the first step toward this flavor-packed Mexican Chicken Fajita Casserole Recipe. Each element plays a starring role: fresh peppers add both crunch and sweetness, quinoa lends a nutritious, protein-rich base, and the combination of salsa and spices brings that signature Mexican zest and warmth.

Thick and chunky salsa (16 ounces): Choose your favorite to set the tangy, saucy tone of the casserole.

Black beans (15-ounce can): Rinsed and drained to add a creamy texture and a boost of fiber.
Fat-free, reduced-sodium chicken broth (14.5-ounce can): Keeps the quinoa moist and infuses gentle savory notes.
Uncooked quinoa (1 cup): Rinsed if needed, this grain cooks perfectly in the casserole, soaking in all the flavors.

Red pepper (cut into 1½ cups strips): Provides sweetness and vibrant color.
Green pepper (cut into 1½ cups strips): Adds a crisp, fresh contrast.
Sweet onion (about 1¾ to 2 cups strips): Balances the peppers with mild pungency and sweetness.

Boneless, skinless chicken breasts or tenders (1 pound): Cut into strips to absorb the seasoning fully and cook quickly.
Olive oil (1 tablespoon): Essential for coating the chicken and veggies to keep everything juicy.
Chili powder (3 teaspoons): Adds smoky depth and a little heat.

Ground cumin (2½ teaspoons): Brings earthy warmth characteristic of Mexican dishes.
Garlic powder (2 teaspoons): Imparts that savory zip without overpowering.
Kosher salt (1½ teaspoons): Enhances every ingredient’s natural flavor.
Optional toppings: Shredded reduced-fat cheese, lettuce, sour cream, avocado or guacamole, chopped cilantro or green onions, and hot sauce like Tapatío to add personalized finishing touches.

How to Make Mexican Chicken Fajita Casserole Recipe

The image shows a white rectangular baking dish with a wooden spoon stirring a mixture of red tomato sauce with chunks, black beans, and small light yellow grains at the bottom. The dish sits on a wooden board with a white towel featuring red stripes underneath it on a white marbled surface. In the background on the left, there is a clear glass bowl filled with raw chicken pieces, sliced white onions, red and green bell pepper strips. To the right, there is a small white bowl with some leftover red sauce and a spoon resting inside. A woman's hand holds the wooden spoon in the baking dish while another woman's hand holds the dish from the bottom. photo taken with an iphone --ar 4:5 --v 7

Step 1: Preheat Your Oven

Start by setting your oven to 400 °F so it reaches the perfect temperature while you prep the ingredients. This ensures your casserole bakes evenly and the flavors meld beautifully together.

Step 2: Combine Salsa, Beans, Broth, and Quinoa

Grab a 9×13 baking dish and lightly coat it with cooking spray to prevent sticking. In the dish, thoroughly mix together the salsa, black beans, chicken broth, and rinsed quinoa. This forms the savory, tangy base that soaks into the quinoa while it bakes, making every bite flavorful and moist.

Step 3: Prepare the Chicken and Vegetables

In a large bowl, toss together the red and green pepper strips, sweet onion strips, chicken strips, olive oil, chili powder, cumin, garlic powder, and kosher salt. Mix until every piece is evenly coated in that vibrant blend of spices and oil, which will infuse the chicken and veggies with that irresistible Mexican fajita flavor.

Step 4: Layer the Pepper and Chicken Mixture

Spoon the seasoned chicken and pepper mixture evenly over the quinoa base in your baking dish. This layering keeps the juicy chicken on top while allowing it to gently steam the quinoa underneath as it cooks.

Step 5: Bake Until Everything is Perfect

Cover the casserole tightly with foil to trap steam and bake for 40 to 50 minutes. Don’t rush this step; the chicken should be fully cooked, the peppers crisp-tender, and the quinoa fluffy and tender with visible “tails” that signify it’s done. This slow bake allows all the ingredients to come together into a harmonious, satisfying dish.

Step 6: Serve with Toppings

Once baked to perfection, remove the casserole from the oven and let it sit for a few minutes. Then, dive in with any of your favorite toppings like shredded cheese, fresh lettuce, creamy sour cream, or a dollop of guacamole to customize each serving.

How to Serve Mexican Chicken Fajita Casserole Recipe

Garnishes

Adding fresh garnishes instantly elevates this casserole. Try a sprinkle of shredded reduced-fat cheese while it’s still warm so it melts nicely, a handful of crisp shredded lettuce for a refreshing crunch, or a dollop of sour cream to add cool creaminess. Fresh avocado, chopped cilantro, or sliced green onions also brighten the dish with vibrant color and fresh flavors.

Side Dishes

This casserole holds its own but pairs beautifully with light sides such as a simple green salad, roasted corn on the cob, or even some tortilla chips and salsa for dipping. These options add complementary textures and keep the meal balanced yet festive.

Creative Ways to Present

For an easy family dinner, serve it straight from the casserole dish and let everyone help themselves. For entertaining, scoop onto colorful plates and add garnishes arranged artfully. You can also portion leftovers into individual ramekins for a convenient grab-and-go lunch option that keeps the fun flavors alive.

Make Ahead and Storage

Storing Leftovers

Place any leftover Mexican Chicken Fajita Casserole Recipe in an airtight container and store it in the refrigerator for up to 3 to 4 days. The flavors actually deepen overnight, making it a fantastic next-day meal.

Freezing

This casserole freezes well, making it a perfect meal prep candidate. Cool completely, then freeze in a suitable container for up to 2 months. Thaw in the refrigerator overnight before reheating to maintain texture and flavor.

Reheating

Reheat leftovers covered in the microwave or in a preheated oven at 350 °F until warmed through. If microwaving, add a splash of chicken broth or water and cover loosely to keep the quinoa moist. Oven reheating keeps the peppers slightly crispier for a close-to-fresh experience.

FAQs

Can I use a different grain instead of quinoa?

Absolutely! While quinoa adds a great protein boost and cooks nicely in this recipe, you can substitute with rice, couscous, or even cauliflower rice for a lower-carb option. Just adjust cooking times accordingly to ensure the grains are tender.

Is it possible to make this recipe vegetarian?

Yes, simply replace the chicken with extra beans or your favorite plant-based protein like tofu or tempeh. You can also add more veggies such as mushrooms or zucchini to bulk it up while keeping the fajita flavors intact.

How spicy is this Mexican Chicken Fajita Casserole Recipe?

The spice level is moderate, mostly coming from chili powder and cumin. If you prefer it milder, reduce the chili powder or omit hot sauce toppings. For more heat, add jalapeños or a dash of cayenne pepper.

Can I prepare this casserole ahead of time and bake it later?

Yes! Assemble the casserole in the baking dish, cover tightly with foil, and refrigerate for up to 24 hours before baking. Just add a few extra minutes to the baking time since it will be cold from the fridge.

What’s the best way to cut the chicken for even cooking?

Cut the chicken into uniform, thin strips about 1/2 inch thick. This size helps the chicken cook quickly and evenly while absorbing the seasoning and remaining tender throughout.

Final Thoughts

This Mexican Chicken Fajita Casserole Recipe is a beloved go-to that brings comfort, bold flavors, and nutritional goodness all in one easy-to-make dish. I promise once you try it, it’ll become a regular in your recipe rotation—perfect for busy nights when you want a satisfying meal with genuine homemade warmth. So grab those simple ingredients, follow these steps, and enjoy a little Mexican fiesta right from your oven!