Boil sorted and shredded sorrel in salted water (1 1/2 litre) and cool. Separately boil 3 beets (whole) with vinegar added to the water.
To the cooled sorrel water, add green onion minced and rubbed together with salt and egg yolk, shredded fresh cucumbers and 1 beet. Beat the yogurt, beet stock, egg white and sugar with a whisk; stir into cooled sorrel water.
Season the ready soup with sour cream and sprinkle with minced dill.