Start by cutting the chicken breasts into bite-sized strips. Toss them with fajita seasoning and set aside.
In a pan, sauté sliced bell peppers and onion in olive oil until they are tender and slightly caramelized.
In another pan, cook the seasoned chicken strips until they are fully cooked and slightly charred.
In a casserole dish, layer tortilla chips, sautéed veggies, and cooked chicken. Repeat the layers as desired.
Sprinkle a generous amount of shredded cheddar cheese over the casserole.
Bake your Chicken Fajita Casserole until the cheese is melted and bubbly.
Garnish your casserole with dollops of sour cream and fresh cilantro for a burst of flavor and color.