Butter your favorite bread, laying one buttered side down on a baking sheet.
Top the buttered sided down with a piece of your desired cheese. Add your favorite filling, caramelized onions for example, on top of the cheese. Top the filling with another piece of cheese and put the other piece of buttered bread on top, buttered side up.
Bake on one side for 8-10 minutes, flip and bake for another 8 or so more minutes.
