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, chiles and cream cheese just until the cream cheese is melted and everything is mixed.
Remove from heat and stir in black beans (if you are using them).
Fill the tortillas with about ⅓ cup of the filling each. Place filled tortillas, seam-side down in the baking dish
Pour enchilada sauce evenly over the enchiladas.
Top with shredded 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.
Top with diced tomatoes before serving (optional)