To cook these, I use a George Foreman Grill.
Brush the top of the sandwich with melted butter. Repeat on the bottom side.
Place one sandwich on your hot Foreman grill. Close the lid and cook for 3-4 minutes. Open the grill, remove the sandwich. Cut on a diagonal with a serrated knife.
It is better to cook them one at a time.
To cook on a stove, heat a heavy skillet over med.-high heat. Place the sandwich in the skillet. Set another heavy pan on top of the sandwich. Cook 2-3 minutes. Flip sandwich over and cook 2 minutes more. When the sandwich is golden brown, remove and cut on a diagonal with a serrated knife.