Preheat oven to 375F. Spray a 9"x13" baking pan with non-stick spray.
Spray a large non-stick skillet with nonstick spray. Heat the chicken, sour cream and cream cheese just until the cream cheese is melted and every thing is mixed.
Removed from heat and stir in black beans (if you are using them).
Place half of the mixture in the prepared baking dish.
Top with half of the tortillas and then half of the cheese.
Repeat with remaining chicken mixture, tortillas and cheese
Cover with foil and bake at 375 for about 30 minutes
Uncover and bake for another 10 - 15 minutes or until bubbly and the cheese on top is slightly browned.