Preheat your oven to 400°F (200°C) and lightly oil a 9x13-inch baking dish.

In a medium bowl, mix cream cheese, tomato sauce, chicken stock, half of the fajita seasoning, salt, and pepper until smooth.

Cut chicken into bite-sized pieces and place in the greased baking dish. Sprinkle remaining fajita seasoning over the chicken, then pour the creamy mixture on top.

Layer bell peppers and onions on top of the chicken, spreading evenly.

Sprinkle shredded cheddar cheese on top and bake for 15-25 minutes, checking for doneness at 15 minutes.

Optional: Broil for the last 2 minutes for a crispy texture.

Let cool for a few minutes before serving with sour cream and avocado if desired.