Spread one slice of bread with 1 tablespoon Dijon mustard. Layer on half of the Gouda cheese, 4 thinly sliced figs, the second half of the Gouda cheese, 1 or 2 slices of prosciutto, and 4 large slices of camembert or brie. Spread one side of the second slice of bread with fig jam, place it on top, of the sandwich, and spread mayonnaise on the outside of the bread.