Onion burger toastie in a panini press

Halve the onion, flatten the cut end and slice thin on a mandolin into a pile; squeeze out the liquid.

Flatten a third of a pound of ground beef to about the size of the bread; season the top.

Mix mayo with a little Dijon mustard for the outside of the bread.

Spray the press top and bottom. Lay in onions, the patty seasoned side down, season the top, more onions; close.

Cook a couple of minutes, aiming for medium rare at about 135; it read 131 after about a minute and a half. Remove the patty.

Wipe the press dry of moisture and let it get hot again.

Build: two slices of American on one slice of bread, the patty with onions both sides, pepper jack, then the other slice spread with mustard mayo.

Place it mayo side down in the press, spread the remaining mayo evenly on the top, close and press down.

Toast about two minutes until golden.