For the cucumber-potato salad, boil the washed potato, covered, until soft, about 25 minutes, rinse and peel, cut into slices.
Halve and seed the peeled cucumber, cut into slices. Fry the bacon in the oil and sauté the diced onion. Heat the soup, stir in the mustard, horseradish and vinegar and pour over the potato-cucumber slice mixture, gently mix with the onion-bacon mixture.
Let the cucumber-potato salad rest for 1/2 hour and then drizzle with the pumpkin seed oil.