For barley soup, wash and boil barley, then strain and rinse. Heat barley in 1 liter of water over low heat.
Wash leek, cut into small pieces and add. Sprinkle in nutmeg and marjoram. Simmer for 2 to 3 hours, adding salt halfway through.
Add water if necessary. Sprinkle the barley soup with walnuts and serve hot.