Peel the cucumber, cut in half lengthways and scrape out the seeds with a teaspoon. Cut the pulp into small cubes, sprinkle with the salt in a bowl and refrigerate.
After a while, drain off the excess liquid and squeeze out the cucumber cubes a little.
Add the peeled, freshly squeezed clove of garlic with the salt to the cucumber in the bowl and mix thoroughly, stir in the kefir or yoghurt and crème fraîche thoroughly. After peeling, pound or chop the walnuts in a mortar. Add half of the finely chopped dill with the nuts to the soup, beat the olive oil underneath - how much you use depends on the taste - and season everything with freshly ground pepper to taste.
Put the soup very cold and then spoon it with bread from deep plates on hot summer days. Sprinkle each plate with the rest of the dill beforehand.