Line a large platter with paper towels. In a skillet over high heat, melt 1 tablespoon of the butter. Turn down the heat to low, add 1 sandwich, and cook, turning once, for 2 to 3 minutes on each side, until browned and crisp on both sides and the cheese is melted. Transfer to the prepared platter to blot the excess grease. Repeat with the remaining butter and sandwiches.