Boil 2 eggs in boiling water for about 10 minutes, quench and peel. Wash the potatoes thoroughly and cook them with their skins in boiling water for about 20 minutes.
Wash the herbs and shake dry. Cut chives into small rolls, chop the rest roughly. Chop kefir, curd, mustard and herbs, except for some cress for sprinkling, finely chop with a hand blender. Season to taste with vinegar, salt, pepper and 1 tbsp. sugar. Coarsely chop boiled eggs and stir into the sauce.
Boil the rest of the eggs in boiling water for about 6 minutes until they are soft and waxy, rinse and peel them. Drain the potatoes and peel as desired. Arrange eggs, sauce and potatoes and sprinkle with rest of cress.
TIP: The sauce tastes good not only with potatoes and eggs, but also with boiled beef or green or white asparagus, aspic, meatballs, maties, steamed fish ...