Well, it's not so much a secret, in fact, it's pretty simple, it may even be written on the inside of the paper label that covers the Underwood Deviled Ham can. It by no means is health food. It's likely one of those depression era recipes - using white bread, butter, mayo, and a questionable meat source.
My mom called them Hot Denver Sandwiches, my family calls them delicious!
For four sandwiches you will need:
2 cans of Underwood Deviled Ham
8 to 16 slices from a block of Monterrey Jack Cheese
Hellmans (or Best Foods) Mayonnaise
8 slices of white, or potato bread
A non-stick 10 inch frying pan
For best results, you should make the sandwiches two at a time.
First, empty one can of deviled ham into a medium bowl with three eggs. Beat with a fork until combined.
Melt a little butter in the frying pan, and heat pan just until the butter begins to brown. Pour the deviled ham egg mixture into the hot pan and swirl gently to be sure it settles evenly. Let it cook until almost solidified, yet still a little bubbly in the middle.
Then, using a spatula, cut the circle into four equal quarters and flip each quarter individually. Lay the cheese on the cooked side immediately and either lower the heat or remove the pan from the heat as soon as the cheese begins to melt.
Stack two quarters per sandwich, cut diagonally, and serve. For two more sandwiches, repeat the whole process. Make your own in the second batch so you can enjoy it while it is still warm and gooey!