pastry rounds may be made 2 days in advance and kept in an airtight container. In a small bowl cream together well the Swiss cheese and the remaining 3 tablespoons butter. Arrange half the pastry rounds, bottom sides up, on baking sheets, divide the cheese mixture among them, and sandwich the mixture with the remaining pastry rounds, pressing the rounds together lightly. Bake the croutes in the preheated 450~ F. oven for 4 minutes, or until the cheese is just melted. Makes about 46 croutes.