Coat a nonstick grill pan or sandwich press with cooking spray. Heat to medium.
Place 4 bread slices on a work surface. Divide the cheese among the four slices and top with peppers. Top each with ham.
Place the remaining bread on the sandwiches and grill on the grill pan or in the sandwich press for 3 to 5 minutes or until cheese is melted (turn sandwiches on grill pan once during cooking).