MIX mustard, pepper puree and mayonnaise with wire whisk until well blended.
FOR each serving: Spread each of 3 toast slices with 1 Tbsp. of the mustard mixture. Cover 1 of the toast slices with 2 salami slices, 1 cheese slice and second toast slice. Top with 2 ham slices, 1 tomato slice, 1 lettuce leaf and remaining toast slice. Cut sandwich in half to serve; secure each half with 4-inch frilled toothpick.