Remove the core of the fennel and its hard stems. Save some green leaves for garnishing if you wish. Cut the fennel in chunks. Peel and cut the potatoes in small cubes.
Heat 2 tbsp of olive in a large saucepan. Add chopped fennel and cook it while continuously mixing until it gets small brown spots. Add potatoes and pour enough water to just cover the vegetables. Throw in a chicken or vegetable cube and bring it to boil. Then let the soup simmer for 10 minutes or until the potatoes are cooked.
Blend the soup using a hand blender until smooth. Distribute into individual bowls, add some olive oil or cream, and the green leaves of the fennel for decoration. Serve with fresh bread.