Preheat and prep: Heat the oven to 400°F (200°C). Lightly grease a 9x13-inch baking dish. Pat chicken dry and cut into small chunks. Slice the peppers and onion thinly.

Season the chicken: In a large bowl, toss chicken with 1 tablespoon olive oil, 2 tablespoons fajita seasoning, and a pinch of salt and pepper. Set aside for 10 minutes while you prep the rest.

Start the veggies: In a skillet over medium-high heat, warm 1 tablespoon olive oil. Sauté sliced onions and peppers with a pinch of salt for 4–5 minutes until slightly softened and a bit charred on the edges. Add garlic and cook 30 seconds.

Mix the base: In the baking dish, stir together sautéed veggies, black beans, corn, Rotel, and lime juice. If using cream cheese, dollop it in small spoonfuls and gently fold. Sprinkle 1/2 cup shredded cheese over this layer.

Add the chicken: Spread seasoned chicken evenly over the veggie mixture. Sprinkle remaining fajita seasoning if you like it bolder.

Bake uncovered: Place the dish in the oven for 18–22 minutes, or until chicken is cooked through (165°F/74°C). Stir halfway if you want more even sauciness, or leave it layered for a defined top.

Cheese time: Remove the casserole, top with the remaining cheese, and bake 5–7 more minutes until melted and bubbly. For golden spots, broil 1–2 minutes, watching closely.

Finish and rest: Let the casserole rest 5 minutes. Taste and adjust salt, pepper, or lime. Sprinkle chopped cilantro on top.

Serve: Spoon into bowls or plates. Add avocado, sour cream, and hot sauce. Serve with warm tortillas, rice, or a crisp salad.