Wash beet, carrot, and potato, dry, and bake wrapped in foil until soft. Peel and dice chilled vegetables.

Slice cucumbers; chop egg whites and greens thinly. Season bread kvass with mustard, salt, and pound egg yolks.

Combine all the foods, cover with the kvass, and leave to stand for 5 minutes.

Serve, garnishing with a dollop of sour cream and ice.