Mix mayo with mustard. Spread a liberal layer of dijon-mayo mixture onto both slices of bread all the way to the edge.

Layer the cheese on one slice of bread followed by the pickles, turkey, beef and ham. You can add another layer of cheese here, or just put the top on the sandwich.

Cut the sandwich on a bias. Wrap each half of the sandwich in a layer of paper towel and put them together on your tin foil. Firmly wrap the sandwich to help prevent cooler water from getting in.