Wash the arugula thoroughly and drain the excess water.
Cut the baguette or ciabatta bread in half.
Lightly brush the inside of the bread with olive oil.
Toast the bread in a pan until golden brown.
Drizzle truffle oil evenly over the toasted bread.
Place prosciutto on top.
Add fresh arugula.
Top with thinly sliced Parmesan cheese.
Season with salt and pepper.
Cover with the other bread half to complete the sandwich.