Wash and quarter unpeeled potatoes. Boil until tender. Fry bacon in pan until crisp, remove from pan, cool and crumble for later use.
When potatoes are tender, drain water and add butter, milk, sour cream, 1⁄2 cup of cheese and seasonings. Mash together and spread into a lightly greased casserole dish. Top with remaining cheese and bacon crumbles.