Name: Chicken Fajita Casserole
Prep time: 15 min
Cook time: 35 min
Total time: 50 min
Cuisine: Tex-Mex
Ingredients: 1 ½ pounds boneless, skinless chicken breasts or thighs, cut into strips; 3 large bell peppers (red, yellow, green), sliced; 1 large onion, sliced; 2 cups shredded cheese (cheddar, Monterey Jack, or pepper jack); 1 can (10 oz) diced tomatoes with green chilies, drained; 2 tbsp olive oil; Juice of 1 lime; Fresh cilantro, chopped (for garnish); Homemade Fajita Seasoning:; 2 tsp chili powder; 1 tsp smoked paprika; 1 tsp ground cumin; 1 tsp garlic powder; 1 tsp onion powder; ½ tsp dried oregano; ¼ tsp cayenne pepper (adjust to taste); Salt and black pepper to taste

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Chicken Fajita Casserole is one of my favorite ways to bring Tex-Mex flavors to the table without spending all evening at the stove. I layer juicy, seasoned chicken with colorful peppers, onions, and plenty of melted cheese for a comforting one-pan dinner that’s as bold in taste as it is easy to prepare.

Chicken Fajita Casserole

Why You’ll Love This Recipe

I like this dish because it transforms the sizzling fajita flavors I enjoy into a baked version that’s hearty and convenient. I don’t need multiple pans or constant stirring—it’s just season, layer, and bake. The homemade fajita seasoning gives a smoky kick without being overwhelming, and I can adjust the spice for anyone at my table. It’s a recipe I turn to when I want something simple, colorful, and satisfying.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

1 ½ pounds boneless, skinless chicken breasts or thighs, cut into strips
3 large bell peppers (red, yellow, green), sliced
1 large onion, sliced
2 cups shredded cheese (cheddar, Monterey Jack, or pepper jack)
1 can (10 oz) diced tomatoes with green chilies, drained
2 tbsp olive oil
Juice of 1 lime
Fresh cilantro, chopped (for garnish)

Homemade Fajita Seasoning:

2 tsp chili powder
1 tsp smoked paprika
1 tsp ground cumin
1 tsp garlic powder
1 tsp onion powder
½ tsp dried oregano
¼ tsp cayenne pepper (adjust to taste)
Salt and black pepper to taste

Directions

I preheat my oven to 400°F (200°C) and lightly grease a 9×13 baking dish.
In a bowl, I mix chicken strips with olive oil, lime juice, and fajita seasoning. I let them marinate for about 10–15 minutes.
I add the sliced peppers and onion to the bowl and toss everything so it’s evenly coated.
I spread half the chicken and veggies in the baking dish, then layer with half the tomatoes and 1 cup of cheese. I repeat with the rest.
I cover with foil and bake for 20 minutes. Then, I uncover and bake another 10–15 minutes until the cheese is melted and golden.
For extra browning, I sometimes broil for 2–3 minutes at the end. I garnish with cilantro and serve with tortillas or rice.

Servings and timing

This casserole serves 6 people. It takes me about 15 minutes to prep and 35 minutes to bake, so I can have it ready in under an hour.

Variations

I like to make a vegetarian version by swapping chicken with mushrooms, black beans, or zucchini.
When I want it extra cheesy, I double the cheese layer and use a mix of cheddar, Monterey Jack, and pepper jack.
For a frontera fajita bowl, I serve it over rice with corn, beans, and avocado.
To keep it low-carb, I skip tortillas and pair it with cauliflower rice or greens.

storage/reheating

I keep leftovers in an airtight container in the fridge for 3–4 days. When I reheat, I prefer the oven at 350°F for 15–20 minutes, which keeps the cheese bubbly. The microwave works too for quick single portions. For longer storage, I freeze the casserole unbaked for up to 3 months, thaw overnight, and then bake as usual.

FAQs

How can I boost the flavor even more?

I find marinating the chicken longer—up to overnight—deepens the flavor. Roasting the peppers before layering also adds a smoky sweetness.

Can I make this ahead of time?

Yes. I often assemble it a day before, cover, and refrigerate. When ready, I bake it straight from the fridge, just adding 5–10 minutes to the cook time.

What toppings go best with this casserole?

I like fresh lime wedges, cilantro, sour cream, salsa, or sliced avocado. Pickled jalapeños also give a nice kick.

Can I swap the protein?

Absolutely. I’ve tried it with shrimp (added in the last 10 minutes), ground turkey (pre-cooked), and even tofu for a vegetarian twist.

Is this recipe spicy?

It can be as mild or hot as I want. If I keep cayenne light, it’s kid-friendly. For spice lovers, I add extra jalapeños or hot sauce on top.

Conclusion

I enjoy making Chicken Fajita Casserole because it captures everything I love about fajitas in a cozy, oven-baked dish. The colors, flavors, and cheesy layers make it feel festive, but the one-pan method keeps it easy enough for any weeknight. Whether I serve it with tortillas, rice, or just as is, it’s always a meal that brings people together around the table.