Wash the potatoes thoroughly, cover and cook in plenty of boiling water for about 20 minutes. Meanwhile, lightly roast pumpkin seeds in a pan without fat, take out immediately and let cool down. Peel and quarter the onion and cut into fine strips. Drain potatoes, rinse with cold water and let them drain. Peel and slice the hot potatoes. Heat stock, vinegar and onions in a pot, season with salt and pepper and add the sunflower oil.
Pour marinade over the warm potato slices and mix carefully. Let the potatoes steep in the marinade for at least 30 minutes and let them cool down. Clean the lamb's lettuce, wash thoroughly several times and drain. Season potatoes with salt and pepper again. Fold in lamb's lettuce, ham and pumpkin seeds and arrange on plates. Sprinkle each with a tablespoon of pumpkin seed oil and serve immediately
Waiting time approx. 20 minutes