Wash the potatoes and cook in boiling water for about 20 minutes. Meanwhile, boil the eggs for about 10 minutes until hard. Then rinse with cold water and peel. Remove egg yolks and pass through a fine sieve.
Season and mix with salt, pepper and mustard. First add oil and sour cream bit by bit, then sour cream. Wash herbs, shake dry, remove coarse stalks. Chop finely with a cradle knife.
Cut the egg white of 3 eggs into strips. Stir the herbs and egg white into the sauce, season again. Drain the potatoes, rinse with water and serve with the green sauce.