01 -
Spread mayo on the outside of both pieces of bread and Dijon on one slice’s inner side. Pile cheeses onto the mustard side.
02 -
Put a skillet over medium-low heat and melt some butter so the bottom is greased evenly.
03 -
Cook the sandwich with a lid on for around 2-3 minutes, letting it brown nicely underneath.
04 -
Flip it over, cover it again, and cook another 1-3 minutes until it’s golden and gooey. If it’s browning too quickly, turn the heat down.