Cut the vegetables finely, mix them with the tomato paste and spices. Spread out the potato puree onto a floured towel. Distribute the stuffing evenly on top, then carefully wrap into a roll.
Transfer to an oiled tray and bake about 45 min. in a preheated 356°F (180 °C) oven. Shortly before its ready you can sprinkle it with grated cheese and crisp it.