Cover the potatoes and cook them in boiling water for about 20 minutes. Wash the tomatoes. Cut tomatoes and mozzarella in about 30 slices each.
Line a baking tray with baking paper. Preheat the oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3). Drain, quench and peel the potatoes. Cut potatoes into approx. 30 slices and place them next to each other on the baking tray.
Season with salt and pepper.
Cover each with 1 slice of salami, tomato and mozzarella, also season the tomatoes with salt and pepper. Bake in a hot oven for about 20 minutes until the mozzarella has melted.