A handful of grated swiss cheese, as much as you dare!
⅓portabella mushroom, thinly sliced
7-8capers, sliced into tiny pieces
Black pepper
Instructions
Spread a thin layer of mayo and mustard over your slices of bread
Add half the swiss cheese to one of the slices
Add the mushrooms
Add the rest of the swiss cheese
Sprinkle the sliced capers on top
Grind some black pepper over the top to taste
Now top with the other slice of bread and cook in your panini or toasted sandwich maker, or on a frying pan over medium heat. If you do the frying pan method, add butter to the outside of the bread too, to crisp it up. I don't do this when I use the panini maker.