Chop the onion and garlic and fry them in a pot with a little olive oil.
In the meantime, chop the fennel and leek. The more green leaves you take from the leek, the more beautiful your soup will be! In terms of taste, however, it makes'no difference.
Add fennel and leek to pot. Sauté briefly. Add water and stir in vegetable broth.
Peel the potatoes and cut them into small cubes. Add them to the soup. Put the lid on and simmer gently for 15 minutes.
Puree the soup and season to taste with salt, pepper and nutmeg.