Preheat oven to 400 degrees.
Peel potatoes and trim to conical shapes. Slice into 1/8-inch thick slices, using a mandoline slicer.
Butter a non stick heavy round mold or a non stick frying pan with a metal handle, about 6 inches across and 2 inch deep.
Arrange potato slices in an even circular pattern. Season and brush with melted butter each layer of potatoes until mold is filled. Cover and bake until potatoes are cooked and well browned.
Unmold on a serving platter like a cake. Cut into 6 equal wedges.