French stick. Cut to size, half it so its still mostly attached at the hinge.
Dijon mustard on the bread.
One side gets a slice or two of
beerwurst as a sandwich meat (comes flat, thin and round), the other side gets a slice of good quality ham. Up the middle add a slice or two of extra mature cheddar on the ham and some sliced up tomato on the wurst. Then over the top/centre you add some egg mayonnaise, made with salad cream and a dash of dijon instead of actual mayonnaise.
Struggle in some way to close it so it mostly ends up being an open top sandwich and devour hungrily.
Depending on what you have in the house corned beef is a good replacement for either meat and some kind of worse cheese is always an option when that is all you have.