- 2 tablespoons olive oil
- 6 cups coarsely chopped cored fresh fennel bulbs (from about 4 large), fronds reserved
- 2 medium onions, chopped
- 8 ounces white-skinned potatoes, peeled, diced
- 4 cups (or more) canned low-salt chicken broth
- 2 teaspoons (or more) fresh lemon juice
- 1 cup whipping cream
- 1 teaspoon fennel seeds, finely crushed
- 3/4 teaspoon dried tarragon
- Heat oil in heavy large pot over medium-high heat. Add fennel bulbs, onions, and potatoes; sprinkle with salt and pepper. Sauté until slightly softened, about 8 minutes. Add 4 cups broth and 2 teaspoons lemon juice; bring to boil. Reduce heat, cover, and simmer until vegetables are very tender, about 30 minutes. Cool slightly.
- Meanwhile, bring cream, fennel seeds, and tarragon to boil in heavy small saucepan. Reduce heat and simmer 5 minutes. Remove from heat; cover and let stand 20 minutes so that flavors blend.
- Working in batches, puree soup in blender until smooth. Return soup to same pot. Stir in cream mixture. Simmer until flavors blend, thinning with more broth if desired, about 5 minutes. Season to taste with salt and pepper and more lemon juice, if desired. (Can be made 1 day ahead. Cool slightly. Chill until cold, then cover and keep chilled. Rewarm over medium heat, stirring occasionally.)
- Ladle soup into 8 bowls. Garnish with reserved fennel fronds and serve.