Dump Cheesy Potato Casserole

1 pound ground beef 2 cans mushrooms -4 oz each (optional) 2 large packages of Augratin Potatoes 4 cups boiling water 1 1/3 cups milk 2 tsp butter 1 tsp salt 1/2 tsp seasoned salt 1/2 tsp pepper 1 cup shredded colby jack cheese Cook ground beef in a skilled until no longer pink. Drain….