Easy Fajita Casserole – One-Pan 30-Minute Dinner

Weeknight dinners can feel like a juggling act – you want something flavorful, but you don't have hours to stand over a hot stove. That's where this Fajita Casserole comes in. It's everything you love about sizzling fajitas – seasoned chicken, bell peppers, onions – but baked into one hearty, cheesy casserole that comes together in about 45 minutes.

I used to make fajitas the traditional way, but on busy nights, the constant stirring and multiple pans felt like too much. So I started layering everything into a baking dish, and it was a game-changer. You get all the smoky, savory flavor with a fraction of the effort, and cleanup is a breeze.

Plus, it's budget-friendly. Using pantry staples and affordable chicken thighs, you can feed a crowd without breaking the bank. And if you're looking to stretch it even further, serve it with rice, tortillas, or a simple salad.

About the Ingredients

1 ½ lbs (680g) boneless, skinless chicken thighs, cut into 1-inch strips

Thighs stay juicy during baking; substitute chicken breast if you prefer, but reduce baking time slightly to avoid drying out.

2 bell peppers (any colors), seeded and sliced into ½-inch strips

Use a mix of red, yellow, and orange for color and sweetness; green peppers work too but are slightly more bitter.

1 large red onion, sliced

Red onion adds color and mild sweetness; yellow or white onion can be swapped in a pinch.

2 cups (240g) shredded Monterey Jack cheese, divided

Melty and mild; cheddar or a Mexican blend also work great.

1 (10-oz / 283g) can diced tomatoes with green chilies (like Rotel), drained

Adds tang and heat; use mild or original, or substitute with 1 cup chopped fresh tomatoes + 1 minced jalapeño.

1 packet (1 oz / 28g) fajita seasoning

Or make your own: 1 tbsp chili powder, 1 tsp cumin, 1 tsp paprika, ½ tsp garlic powder, ½ tsp onion powder, ¼ tsp cayenne.

8 small flour tortillas (6-inch), cut into 1-inch strips

Corn tortillas work for a gluten-free option; stale tortillas are perfect for this.

½ cup (120ml) chicken broth

Keeps the casserole moist; vegetable broth works too.

2 tbsp olive oil

For sautéing; avocado oil is a good high-heat substitute.

Salt and black pepper, to taste

Always taste and adjust; fajita seasoning can be salty, so go easy on added salt.

Optional toppings: sour cream, salsa, fresh cilantro, lime wedges

Add these after baking for freshness and extra flavor.

Tips & Tricks

Don't Overcook the Chicken

If using breast, check for doneness at 25 minutes; thighs can go the full 35 minutes. Overcooking makes chicken rubbery.

Let It Rest

After baking, let the casserole sit for 5-10 minutes. This allows the juices to redistribute and makes it easier to serve clean slices.

Drain the Tomatoes

Don't skip draining the canned tomatoes – excess liquid can make the casserole watery. Press them lightly with a spoon to remove extra juice.

Step-by-Step Instructions

1. Preheat Oven

Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with nonstick spray.

2. Sauté Aromatics

In a large skillet, heat olive oil over medium-high heat. Add the sliced peppers and onion, and sauté for 5-7 minutes until they begin to soften and get slightly charred at the edges.

3. Add Chicken

Add the chicken strips to the skillet, sprinkle with fajita seasoning, salt, and pepper. Cook for 5-6 minutes, stirring occasionally, until the chicken is browned on the outside but not fully cooked through (it will finish in the oven).

4. Mix with Tomatoes

Stir in the drained diced tomatoes with green chilies and chicken broth. Let it simmer for 2 minutes, then remove from heat.

5. Layer Tortillas

Spread half of the tortilla strips evenly over the bottom of the prepared baking dish. Top with half of the chicken-vegetable mixture, then sprinkle with 1 cup of shredded cheese.

6. Repeat Layers

Repeat with the remaining tortilla strips, chicken mixture, and the remaining 1 cup of cheese, making sure the top is covered with cheese.

7. Bake Covered

Cover the dish with foil and bake for 25 minutes. The casserole should be bubbly and the cheese melted.

8. Brown the Top

Remove the foil and continue baking for an additional 10 minutes, or until the cheese is golden brown and the edges are bubbling. If you like a crispier top, broil for 1-2 minutes, watching closely.

9. Rest and Serve

Let the casserole rest for 5 minutes before serving. Garnish with fresh cilantro, sour cream, and lime wedges if desired.

Delicious Variations

Steak Fajita Casserole

Substitute 1 lb (450g) of thinly sliced flank steak for chicken, and cook until just browned before layering.

Vegetarian Fajita Casserole

Swap the chicken for 2 cups of black beans (drained) or extra firm tofu, and use vegetable broth.

Low-Carb Option

Replace the tortilla strips with a layer of cauliflower rice, and use low-carb tortillas or omit them entirely.

How to Store Fajita Casserole Recipe

Frequently Asked Questions

I hope this Fajita Casserole becomes a regular in your dinner rotation! If you try it, I'd love to hear how it turned out – what did you serve it with? Drop a comment below and let's chat! Small steps, big impact.

Fajita Casserole Recipe

This Easy Fajita Casserole brings all the sizzling flavors of classic fajitas into one comforting, cheesy baked dish the whole family will love.

★★★★½ 4.8 (127 ratings)

15 minPrep time35 minCook time6Servings285 kcalCalories

Print RecipePin Recipe

🧂 Ingredients

• 1 ½ lbs (680g) boneless, skinless chicken thighs, cut into 1-inch strips
• 2 bell peppers (any colors), seeded and sliced into ½-inch strips
• 1 large red onion, sliced
• 2 cups (240g) shredded Monterey Jack cheese, divided
• 1 (10-oz / 283g) can diced tomatoes with green chilies (like Rotel), drained
• 1 packet (1 oz / 28g) fajita seasoning
• 8 small flour tortillas (6-inch), cut into 1-inch strips
• ½ cup (120ml) chicken broth
• 2 tbsp olive oil
• Salt and black pepper, to taste
• Optional toppings: sour cream, salsa, fresh cilantro, lime wedges

📋 Instructions

1. 1Preheat Oven — Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with nonstick spray.
2. 2Sauté Aromatics — In a large skillet, heat olive oil over medium-high heat. Add the sliced peppers and onion, and sauté for 5-7 minutes until they begin to soften and get slightly charred at the edges.
3. 3Add Chicken — Add the chicken strips to the skillet, sprinkle with fajita seasoning, salt, and pepper. Cook for 5-6 minutes, stirring occasionally, until the chicken is browned on the outside but not fully cooked through (it will finish in the oven).
4. 4Mix with Tomatoes — Stir in the drained diced tomatoes with green chilies and chicken broth. Let it simmer for 2 minutes, then remove from heat.
5. 5Layer Tortillas — Spread half of the tortilla strips evenly over the bottom of the prepared baking dish. Top with half of the chicken-vegetable mixture, then sprinkle with 1 cup of shredded cheese.
6. 6Repeat Layers — Repeat with the remaining tortilla strips, chicken mixture, and the remaining 1 cup of cheese, making sure the top is covered with cheese.
7. 7Bake Covered — Cover the dish with foil and bake for 25 minutes. The casserole should be bubbly and the cheese melted.
8. 8Brown the Top — Remove the foil and continue baking for an additional 10 minutes, or until the cheese is golden brown and the edges are bubbling. If you like a crispier top, broil for 1-2 minutes, watching closely.
9. 9Rest and Serve — Let the casserole rest for 5 minutes before serving. Garnish with fresh cilantro, sour cream, and lime wedges if desired.

👨‍🍳 Chef's Note: For a smoky twist, try using smoked paprika in the seasoning blend. It adds a subtle depth that mimics the char of a grill.

Servings: 6

Cuisine: Mexican-inspired

Course: Casserole

Nutrition (per serving): 285 kcal · 12g protein · 22g carbs · 9g fat

Written by Elena Vasquez

Elena writes about sustainable living and practical zero-waste swaps for everyday families. She focuses on small, budget-friendly changes that make a big difference over time.