Boil eggs and potatoes, peel them and then let cool down completely.
Meanwhile, coarsely grate the cucumber and mix with the juice into the kefir. Cut the radishes, potatoes, eggs and sausage into small cubes. Add to the kefir and season with dill, lemon juice, pepper and salt.
Allow to steep in the refrigerator for at least 12 hours before consumption. Serve cold, sprinkled with chives.