How to Make It
Preheat oven to 425°F with rack in upper third of oven. Place butter on a rimmed baking sheet, and place in preheated oven until butter melts, about 5 minutes.
Spread goat cheese evenly on 5 of the bread slices. Arrange bread slices with goat cheese and plain bread slices in a single layer in melted butter on baking sheet. Place 1 Cheddar slice on each bread slice with goat cheese, and place 1 slice each of provolone and Swiss on each plain bread slice. Return to oven, and bake at 425°F until cheese is bubbly and bread begins to brown, about 7 minutes.
Remove from oven, and assemble sandwiches. Return to oven, and bake until bread is golden and toasted, 3 to 4 minutes.