This Baked Fajita Chicken Casserole is an easy one-pan recipe. Simple to make, my version is made with boneless, skinless chicken thighs, bell peppers, mushrooms, onions and cheese. Perfect to serve over rice, cauliflower rice or gluten-free pasta, this cheesy chicken fajita bake can be ready in about 45 minutes.
Prepare the vegetables and aromatics (onions and garlic). Slice the onion, peppers and mushrooms, mince the garlic, and grate the cheese.
Cut the chicken thighs into bite-sized pieces. Sprinkle all over with fajita seasoning.
Heat oil in a large oven-proof skillet over medium heat. Add the onions, peppers and mushrooms and sauté until the onions are translucent and the peppers have softened, 4 to 5 minutes.
Add the minced garlic to the skillet and cook for another minute or two, stirring to distribute it evenly.
Transfer the vegetables and aromatics to a bowl.
Add the chicken pieces to the hot skillet. Brown the chicken on all sides for about 5 minutes.
Add the vegetables and aromatics back into the skillet on top of the chicken.
Sprinkle with grated cheese.
Bake for 15 minutes or until cheese has melted and the internal temperature of the chicken is at least 165°F.
Remove from the oven, sprinkle with chopped parsley or cilantro and add optional toppings.
Notes
To make fajita seasoning, combine in an 8-ounce jar: