Oklahoma onion burger patty melt

Mix mayo with Dijon mustard; it goes on the inside of the sandwich and on the outside of the bread before it is grilled.

Slice a peeled half onion thin on a mandoline into a good pile.

Spread mustard mayo on one side of each slice of bread and griddle that side on the flat top until well crisp, so the sandwich is not wibbly.

Melt beef tallow on the flat top, put down the patty balls and season with the rub.

Pile sliced onions on each and smash flat.

Flip; put two slices of cheese on each patty and stack the patties.

Put mayo on the bottom of one piece of bread, face down; add the patties and the other bread on top; squish, mayo the top, and flip until well colored on both sides.

Cut in half.