Preheat your oven to 375°F (190°C) and prepare a 9x13-inch baking dish by greasing it lightly.

In a large non-stick skillet over medium heat, sauté the boneless chicken for about 8-10 minutes until cooked through, seasoning with fajita seasoning during the last minute.

Remove the chicken, then sauté diced bell peppers and onions in the same skillet for 5-7 minutes until tender.

In the greased baking dish, combine cooked chicken, sautéed vegetables, and cream cheese, stirring until evenly coated.

Sprinkle shredded cheese generously over the mixture.

Bake for about 30 minutes until cheese is bubbly and golden brown.

Let cool for 5 minutes before serving, topped with sour cream and avocado.