In a large bowl, combine the soup, sour cream and garlic salt. Add potatoes and cheddar cheese; mix well. Pour into a greased 13-in.x9-in.x2-in. baking dish. Top with Parmesan cheese. Bake, uncovered, at 350 for 55-60 minutes or until potatoes are tender. Recipe by: Taste Of Home - February/March 1997 Posted to EAT-L Digest 29 Jan 97 by The Taillons on Jan 30, 1997.