Cheesy Chicken Fajita Casserole with Rice and Peppers Step-by-step instructions

Before you start

Before you begin cooking, organize and measure all of your ingredients to ensure a smooth, seamless assembly. Cut the boneless, skinless chicken breasts into uniform half-inch cubes and place them in a bowl in the refrigerator until ready to cook.

Dice the red and green bell peppers, measure out the pre-cooked rice, and freshly grate the cheddar and Monterey Jack cheeses. Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish with a thin layer of vegetable oil or nonstick cooking spray.

Instructions

Sautéing the Seasoned Chicken and Bell Peppers

1. 1Sauté the Chicken and Seasoning
   Heat a large skillet over medium-high heat. Add the chicken breast chunks and sprinkle the fajita seasoning evenly over the top. Cook, stirring occasionally, for 5 to 6 minutes until the chicken starts to brown on all sides.
   Look for The chicken pieces should be lightly browned on the edges.
   Tip Do not overcrowd the skillet so the chicken sears instead of steaming.
2. 2Add the Bell Peppers
   Stir the diced red bell pepper and green bell pepper into the skillet with the chicken. Continue to sauté for 4 to 5 minutes until the peppers are tender-crisp and the chicken is fully cooked, reaching an internal temperature of 165°F (74°C).
   Look for The peppers should be bright and slightly softened.
   Safe temperature 165°F (74°C) internal temperature (poultry)
   Tip Keep the heat medium-high to get a nice char on the peppers.

At the end of this first phase, the chicken chunks should be completely opaque, beautifully browned on the edges, and fully coated in the fragrant fajita spices. The red and green bell peppers will look bright and glistening, having softened slightly while still retaining a gentle crunch.

You should hear a gentle sizzle in the skillet, and the kitchen will be filled with the warm, aromatic scent of toasted cumin, chili powder, and garlic. Ensure the chicken has reached a safe internal temperature before moving to the assembly.

Combining and Assembling the Casserole

3. 3Mix the Rice and Cheese
   In a large mixing bowl, combine the cooked long-grain white rice and half of the shredded cheddar cheese and Monterey Jack cheese. Stir well until the mixture is fully combined.
   Look for The mixture should look uniform.
   Tip Ensure the rice is slightly warm to help the cheese begin to melt and bind.
4. 4Assemble the Casserole Base
   Gently fold the sautéed chicken and bell pepper mixture into the rice and cheese mixture until evenly distributed. Transfer the entire mixture into a 9x13-inch baking dish, spreading it into an even layer with a spatula.
   Look for The casserole base should be flat and evenly distributed.
   Tip Lightly grease the baking dish to prevent the rice from sticking.

By the end of the assembly phase, the rice, sautéed chicken, bell peppers, and half of the cheese should be fully integrated into a cohesive mixture. The spices from the chicken will have lightly colored the rice, creating a beautiful, vibrant base. When you transfer this mixture to the prepared baking dish, it should spread easily and evenly, forming a flat, moist foundation that is ready to be topped with the remaining shredded cheeses.

Bake to Cheesy, Bubbling Perfection

5. 5Top with Remaining Cheese
   Sprinkle the remaining shredded cheddar cheese and Monterey Jack cheese evenly over the top of the assembled casserole, covering the rice and chicken mixture completely.
   Look for The cheese should form an even blanket over the top.
   Tip Mix the two cheeses together before sprinkling for a beautiful marbled look.
6. 6Bake Until Golden and Bubbling
   Bake in the preheated oven at 375°F (190°C) for 15 to 20 minutes. The casserole is done when the cheese is completely melted and golden brown, and the juices are bubbling vigorously around the edges of the baking dish.
   Look for The cheese should be bubbly and golden brown.
   Tip Let the casserole rest for 5 to 10 minutes before serving to let it set.

As the casserole finishes baking, the shredded cheddar and Monterey Jack cheeses will have completely melted into a luxurious, golden-brown blanket across the top. You will see rich, savory juices bubbling vigorously around the edges of the baking dish, and the cheese will pull in long, dramatic, stretchy strands when lifted with a spoon.

The entire kitchen should smell incredibly savory, with notes of toasted cheese and seasoned Tex-Mex spices signaling that the dish is ready to be removed from the oven.

Common mistakes

One common mistake is overcooking the chicken during the initial sauté phase; remember that the chicken will continue to cook and heat through during its fifteen to twenty minutes in the hot oven, so sautéing it just until it reaches the safe temperature of 165°F (74°C) is key to keeping it tender and juicy. Another frequent error is using pre-shredded cheese from the store, which contains starches that prevent it from melting into that signature ultra-stretchy blanket.

How to tell it’s done

To determine if the casserole is perfectly done, look for active, rapid bubbling around the entire perimeter of the baking dish and a beautifully melted, lightly browned cheese crust on top. Because the chicken is fully cooked before entering the oven, the baking time is primarily focused on melting the cheese and heating the interior.

To be absolutely certain, insert an instant-read thermometer into the center of the casserole; it should read at least 165°F (74°C), ensuring the poultry is safe and the entire dish is piping hot throughout.

• Poultry: 165°F (74°C) in the thickest part