Zuppa di finocchio is a traditional soup made with fennel as the star ingredient. Although there are many variations across the country, the soup is often made with a combination of fennel bulbs, leeks, potatoes, chicken stock, butter, olive oil, salt, and pepper.
The leeks are cut in half lengthwise, chopped, and sautéed in butter and oil until soft. The fennel, potatoes, stock, salt, and pepper are then added to the pot and simmered until the vegetables are soft. They're processed until smooth, returned to the pot, and reheated.