Toast the croissant if desired then carefully cut in half.
Cut the tomato into thin slices and the mozzarella cheese into slices bout 1 cm thick.
Clean some anchovy fillets then let them marinate in olive oil. In order, place the tomato slices, mozzarella cheese and then anchovy fillets on the croissant.
Layer olive oil on top and decorate with sprout leaves for a tasty sandwich!