This crostini is typical of the area around Naples and on the island of Capri, and is meant to resemble the popular pizza con carciofi, or pizza with artichokes.
In a medium-size bowl, mix the mozzarella, chopped artichoke bottoms, olives, tomato, olive oil, chopped anchovies, and oregano and season with salt and pepper. Place about 1 tablespoon of this mixture on each slice of bread. Arrange the bread on a broiler tray or baking sheet and place a half anchovy fillet on top along with 1 or 2 capers.