Split the English muffins open and arange on a tray. Stir together the mayonnaise and the Dijon mustard; spread evenly on the muffins.
Place a slice of ham on four of the English muffins and top with a piece of rolled omelet. Finish with a slice of cheese and top with the second half of the muffin.
Wrap the sandwich in paper towel and then a large sheet of parchment paper, making sure that it is airtight. If you are freezing these for a month or more, also wrapt them in foil. Freeze solid.
To enjoy, remove foil and place in the centre of a microwave on a microwave safe plate. Heat for 1 1/2 - 2 minutes on medium high. Microwaves may vary.