Since the artichoke hearts are used raw in this recipe, only very young ones are suitable. The best artichoke hearts found in Tuscany are the exceptionally small Morellini. They do not contain hay and their tender leaves can be eaten without any problem. Mammoli are also recommended, although they are a little larger, but without spiny leaf tips.
Preheat the oven to 180 °C. Toast the bread slices on a baking tray for about 5 minutes until golden brown, turning once to the other side.
Meanwhile, remove the hard outer leaves and the hay (if any) from the artichoke hearts. Cut them lengthwise into narrow slices and place them in a large enough bowl of water that has been acidified with the juice of a lemon – this will prevent them from darkening. Finely shave the Parmesan cheese.
Drain the artichoke hearts and dry them thoroughly in a towel or with kitchen roll. Arrange the bread slices on individual plates, top with the artichoke hearts and spread the Parmesan evenly on top. Season with salt and pepper, drizzle with oil and bring to the table.