Preheat the Oven to 400°F (200°C) and oil a 9x13-inch baking dish.

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

Toss the chicken with remaining fajita seasoning and arrange in the baking dish.

Spread the cream cheese mixture over the chicken and layer with bell peppers and onions.

Sprinkle shredded cheese on top.

Bake for 15 to 25 minutes or until chicken reaches 165°F (74°C). Optionally broil for 2 minutes.

Let rest for 5 minutes before serving topped with avocado or sour cream.