Chicken Fajita Casserole, One Dish Tex-Mex

This is my go-to chicken fajita casserole recipe, and it never lets me down.

Fajitas are great, but there’s a lot of skillet-juggling and tortilla-warming standing between you and dinner most nights. This casserole takes everything good about fajita night, tender chicken, colorful peppers, that tangy Rotel kick, and lets it all bake together in one dish while you do basically nothing.

It’s earned a reputation as one of the most popular weeknight dinners in a lot of households for exactly that reason — genuinely big flavor with very few dishes to clean up afterward.

Why You’ll Love This

It has amazing flavor and comes together with very few dishes, since everything bakes together in one casserole dish. Tender chicken, rice, vibrant peppers, and tangy Rotel tomatoes come together under a blanket of melty cheese, and it’s a genuinely fast, low-fuss way to get fajita flavor on the table.

Why This Works

Using frozen peppers and onions rather than fresh is a deliberate choice here — because the casserole’s baking time is relatively short, frozen vegetables cook through faster and end up with a softer texture that suits a baked dish better than fresh, which can stay too crisp. And using instant rice rather than regular long-grain is what lets the rice fully cook and absorb the sauce in the same bake time as everything else, since regular rice would need considerably longer to soften.

How to Make Chicken Fajita Casserole

Step 1: Preheat and Prep

Preheat your oven to 350°F and lightly grease a 9×13-inch baking dish.

Step 2: Combine the Base

In a large bowl, combine the shredded chicken, instant rice, cream of chicken soup, sour cream, frozen pepper and onion blend, undrained Rotel tomatoes, chicken broth, and fajita seasoning. Stir until well combined.

Step 3: Assemble the Casserole

Pour the mixture into the prepared baking dish, spreading it out evenly.

Step 4: Top with Cheese

Sprinkle the shredded Mexican blend cheese evenly over the top.

Step 5: Bake

Bake, covered, for about 30 to 35 minutes, until the rice is tender and the mixture is heated through. Remove the cover for the last 10 minutes to let the cheese melt and turn golden.

Step 6: Rest and Serve

Let the casserole rest for a few minutes before serving.

Tips for the Best Results

• Use instant rice rather than regular rice, since it’s designed to cook fully within the casserole’s bake time.
• Frozen pepper and onion blends work best here for their softer texture and faster cook time, though you can sauté fresh vegetables first if you prefer more bite.
• Choose your fajita seasoning’s heat level to taste, and use the mild or hot version of Rotel depending on your preference.
• A low-sodium broth is a good option if you’re watching sodium, since the seasoning packet and Rotel both add plenty of salt on their own.
• Let the casserole rest a few minutes after baking so it’s easier to serve neat portions.

Variations to Try

Use chicken thighs in place of breast meat for a juicier result. Swap the Mexican blend cheese for cheddar, mozzarella, or fontina depending on what you have. Add black beans or corn for extra texture and fiber.

What to Serve With It

Serve with tortilla chips and guacamole on the side for extra crunch and freshness. A simple green salad also works well if you want something lighter alongside.

Storage and Reheating

Store leftovers in an airtight container in the fridge for up to 4 days. Reheat in the microwave or a covered dish in the oven until warmed through.

FAQ

Can I use fresh peppers and onions instead of frozen?

Yes, though you may want to sauté them first in a hot skillet for extra flavor and to ensure they soften properly in the shorter bake time.

Can I use regular rice instead of instant?

It’s not recommended, since regular rice needs considerably longer to cook than the casserole’s bake time allows.

How spicy is this casserole?

It depends on your choice of Rotel and fajita seasoning — use the mild versions for a gentler dish, or hot versions if you want more kick.

Can I use pre-cooked rotisserie chicken?

Yes, shredded rotisserie chicken works perfectly and saves time.

How long do leftovers keep?

Up to 4 days in an airtight container in the fridge.