Wash the potatoes and cook for 15-20 minutes in boiling water. Then rinse with cold water, peel and let the potatoes rest. In the meantime, boil eggs in boiling water for about 8 minutes, rinse cold and peel. Peel and finely dice onions. Cut cucumbers into slices. Cut the eggs into eighths or dices, cut the potatoes into slices.
Bring the stock and diced onion to the boil. Season with salt, pepper and sugar. Drizzle hot over the potatoes. Stir mayonnaise, yoghurt, cucumber water and mustard until smooth. Mix potatoes, eggs, cucumber and mayonnaise. Cover and leave to stand for at least 1/2 hour.
Wash the chives and cut into small rolls. Season the salad again, if necessary add more seasoning. Sprinkle with chives. Add hot sausages.