Grilled Cheesburgers
rec.food.recipes/HANDO (Carol) (1994)
I don't know if this will work with the "new type" sandwich makers, but we used to do these on the "old fashion" flat sandwich grills.

Hamburger
Onions, thinly sliced
American Cheese slices (or Velveeta)
White sandwich bread

Spread a THIN layer of hamburger on one piece of bread. (Don't try to make a patty and lay it on the bread as it will be too thick and not cook quickly enough, and will also be too juicy.) You should be able to still see some of the bread through the hamburger. Top with the onion, cheese slice and another slice of bread. We buttered the outside since this will pre-nonstick coating days. Grill until the cheese starts to run out.

Good way to make lots of cheeseburgers with very little burger.