1. Melt the butter in a large saucepan and add the scallions, fennel, celery, carrots and cumin. Cover and cook for about 5 minutes or until soft.
2 Add the diced potatoes and chicken or vegetable stock, and simmer the mixture for another 10 minutes.
3. Liquidize the soup in the pan with a hand-held blender. Stir in the cream and season to taste. Serve in individual soup bowls and garnish with chopped parsley.
Tip : For convenience, you can freeze the soup in portions before adding the cream, seasoning and parsley.