Clean, wash and chop the leek. Peel, wash and dice parsley root, carrots, celery and potatoes. Heat the oil in a large pot and sauté the vegetables in it.
Deglaze with broth and cook over medium heat for about 20 minutes. In the meantime wash herbs and pat dry. Cut chives into rings. Cut marjoram finely and mix with sour cream. Season with salt, pepper and sugar.
Season soup with salt, pepper, nutmeg and 1 pinch of sugar. Serve the soup, sprinkle with chives. Add the sour cream. Baguette bread tastes good with it.