Split the loaf and spread with mustard and mayonnaise. Layer the remaining ingredients and top with the other half of the bread. Lightly butter the OUTSIDE of the bread and wrap the sandwich in aluminum foil. Place on a skillet over low heat. Squish it with a heavier skillet on top of the wrapped sandwich and keep it there for a minute or two. Flip over and repeat for another minute or two. Unwrap and eat.
For the most authentic taste, don't use standard processed cold cuts. Try making it after Thanksgiving when you are likely to have both leftover turkey and ham. If you must use cold cuts, at the very least, make sure they sliced thickly, or use more than indicated. This sandwich is usually made using Cuban bread. If you can't find it, substitute any crusty bread such as French or Italian. It is also usually pressed in a sandwich iron. If you don't have one, use a skillet as described.