They are loaded with a sandwich of diminutive filling (my mom used cold pot roast), buttered on both exterior bread sides and placed in the circular iron, which cuts off the extra bread, and put over an open flame. The edges of bread that overlap the iron burn off and the edges seal from the hot pressure of the clamped iron. About 1 minute per side on an already hot iron. What comes out is a perfect double convex circle sealed at the circumference and molten in the center. Also, because of the markings on the iron, the sandwich pocket is decorated with toasted concentric circles. The art of it comes in just the right amount and composition of the filling. Cream cheese is great. It was really popular becaue it not only used up leftovers but because it allowed for a very high ratio of starch to protein. Very economical, not unlike a little meat and alot of rice.