How to Make It
Put the drained white beans, pancetta, halved onion, whole garlic cloves and bay leaf in a medium saucepan. Add the 3 cups of water and bring to a boil over high heat. Reduce the heat to low, cover the saucepan and simmer until the beans are tender, about 1 1/2 hours. Discard the pancetta, onion, garlic and bay leaf.
Meanwhile, in a large, heavy pot, heat the olive oil. Add the fennel, potatoes, chopped onion and smashed garlic. Cover the pot and cook the vegetables over moderately low heat, stirring occasionally, until the fennel and onion are softened, about 10 minutes. Add the 2 quarts of water and gradually bring to a boil. Reduce the heat and simmer for 30 minutes.
Add the zucchini and green beans to the pot and simmer for 20 minutes. Mash the potatoes against the side of the pot using a large fork; the potatoes will thicken the soup. Add the diced tomatoes and the white beans and their cooking liquid and simmer the soup over moderately low heat for 5 to 10 minutes.
In a small skillet, melt the butter. Add the pasta and cook over moderate heat until golden brown and toasty, about 4 minutes. Stir the pasta into the soup and simmer for 1 minute. Cover, remove from the heat and let stand until the pasta is tender, about 25 minutes. Season with salt and pepper.
Put the Classic Pistou in a large soup tureen. Gradually stir in some of the liquid from the soup, then pour in the rest of the soup and stir well. Ladle the soup into bowls, garnish with basil sprigs and serve hot or at room temperature.
One Serving 323 Calories, 14 gm Fat, 4.2 gm Saturated Fat, 39 gm Carbohydrates, 12 gm Fiber.