Cut the ciabatta bread in half.
Spread pesto sauce evenly on the inside of both bread slices.
Place sliced ham on one half of the bread.
Add sliced cheese on top of the ham.
Optionally add tomato slices or arugula.
Cover with the other piece of bread.
Add a little olive oil to a pan and toast the sandwich on medium-low heat until golden on both sides.
Cut into serving-size pieces and plate.