Grilled Tomato and Mozzarella sandwiches

1 loaf sliced white sandwich bread   (**I think I would use Sourdough**)
2 pounds salted fresh mozzarella cheese, sliced 1/4 inch thick
4 medium tomatoes, sliced 1/4 inch thick
2 ounces (4 T) unsalted butter, softened

1. Using a 2 1/2 inch round cookie cutter (cup?) cut out bread and mozzarella.

2. Season tomatoes with salt and pepper. Sandwich 1 tomato slice and 1 mozzarella slice between 2 slices of bread. Repeat with remaining tomatoes, mozzarella and bread to use up
loaf of bread.

3. Preheat grill to medium, or heat a grill pan over medium heat. Brush outsides of bread with butter. Grill sandwiches until golden brown and mozzarella is soft but not completely melted, about 5 minutes per side.