To a large bowl add in the cream of soup, milk, seasonings, water, and broth whisk well now add in the chicken, pasta, and mushrooms.
Spray a large casserole dish or 9x13 baking dish with non stick spray. Place the casserole into the baking dish and spread out cover with foil and bake for 40 minutes.
Uncover and stir in the sour cream and sprinkle the cheese over the top bake for an additional 10 minutes.