Method

1. Preheat the oven to 350°F / 180°C.
2. Toss the fennel and onions with 1 tablespoon of oil on a large heavy baking tray to coat. Roast in the oven for 25 minutes, stirring occasionally, or until the fennel and onions are tender.
3. Heat the remaining 1 tablespoon of oil in a large heavy saucepan over medium heat. Add the garlic and sauté for 1 minute. Add the leeks and sauté for 5 minutes, or until softened slightly. Add the broth, potatoes, and roasted fennel mixture and bring to a simmer.
4. Continue simmering for 18 minutes or until the potatoes are very tender. Remove the soup from the heat and cool slightly.
5. Working in batches, puree the soup in a blender until smooth. Strain the soup into a clean large saucepan. Add the cream to the soup and bring to a simmer over medium-high heat, stirring occasionally.
6. Season to taste with salt and pepper.
7. Ladle the soup into bowls then garnish with the chives and serve.