Step 1

Melt butter in a large pot over medium heat. Add fennel; cook and stir until fragrant, about 5 minutes. Stir in leeks; cook until slightly softened, 3 to 5 minutes. Add potatoes and broth. Bring soup to a boil; reduce heat and simmer until vegetables are very tender, about 15 minutes.

Step 2

Puree soup with an immersion blender until smooth. Add carrots and red bell pepper; simmer until softened, about 5 minutes. Remove from heat. Stir in heavy cream and anise-flavored liqueur. Season with salt and white pepper.