Wash the potatoes and cook covered for about 20 minutes. Boil eggs hard. Quench potatoes and eggs, peel and let cool down.
Peel onions and carrots. Wash the carrots. Finely dice both. Fry in hot oil. Deglaze with 100 ml water and vinegar. Bring to the boil and stir in the stock. Simmer for about 5 minutes. Season with salt, pepper and some sugar.
Quarter the potatoes and pour the hot marinade over them. Leave to stand for about 1 hour.
Finely dice the cucumbers. Wash and chop the chives. Mix with mayonnaise and yoghurt. Season and mix with the potatoes. Coarsely chop the eggs, fold in. Leave to stand for at least 1 hour. Flavour again.