Boil the potatoes in the skins until soft, cut in half lengthways, place the cut surface up on a greased baking sheet, sprinkle with a little salt.
Put the tomatoes in a pan, season with the Italian herb mixture, rosemary, salt and pepper. Reduce the liquid over a medium heat, stirring occasionally. Allow to cool a little, distribute on the potatoes, smooth out.
Place the mozzarella, ham or salami and the olives on top of the tomatoes one after the other, sprinkle with grated Parmesan and pepper.
Preheat the oven to 220 ° C, bake on the middle rack for 12-15 minutes.