Onions peel and chop finely. Peel and wash carrots and kohlrabi. Cut both into fine sticks. Clean and wash the leek and cut into rings
Heat the oil in a pot (preferably coated). Sauté onions and vegetables in it while stirring. Season with salt and pepper and deglaze with 1 l water. Bring everything to the boil, cover and simmer for 10-15 minutes
Wash the chives and cut into small rolls. Season soup with salt, pepper and possibly some Worcester sauce. Sprinkle the chives over it