1. Combine rutabagas, 1 tsp. salt, and 6 cups water in a large Dutch oven; bring to a boil, and cook 25 minutes. Add turnips, and cook 20 more minutes or until vegetables are tender; drain.
2. Combine vegetables, cheese, and next 4 ingredients in a large mixing bowl; mash with a potato masher (or beat at medium speed with an electric mixer) to desired consistency. Stir in bourbon, if desired.