Clean the M. Portobello (if necessary) with a brush or a damp piece of kitchen paper.

Fry the hamburger on the grill until done.

Put the M. Portobello's and the onion on the grill and add olive oil. Fry for about 2-3 minutes and turn over.

For the last 2 minutes, put the cheese on the M. Portobello's until the cheese has melted.

Portobello

Mayo

Lettuce, tomato, cucumber

Hamburger with cheese and onion

Ketchup

2nd Portobello

Enjoy!