White Bean Bouillon with Mascarpone Raviolini

• 1/4 cup extra virgin olive oil
• 2 stalks celery, any tender leaves reserved, stalks peeled and chopped
• 1 medium white onion peeled and chopped
• 1 pound dried white beans (such as tarbais or navy beans)
• 2 sprigs sage
• 1/4 cup kosher salt
• 1 1/2 teaspoons freshly ground white pepper
• 30 to 36 Mascarpone Raviolini
• 1/4 cup hazelnuts, toasted and chopped
• 1 tablespoon hazelnut oil
• 1 teaspoon lemon juice Fleur de sel 
• 6 celery leaves, chopped 
• Shaved truffles (optional)

In a soup pot, heat the olive oil over medium heat. Add the celery and onions and cook, stirring occasionally, until translucent but not browned, about 10 minutes. Add the beans and 2 quarts of water. Add the sage, bring to a boil, lower to a simmer and cook, partially covered, until beans are soft, about 2 1/2 hours. Remove the sage and purée the soup in a blender. Pass the soup through a fine mesh strainer and season with the salt and pepper. Add a little more water to the soup if it’s too thick.

To cook the prepared raviolini, drop the raviolini into a pot of boiling salted water. Stir gently and let cook until they float, 3 to 4 minutes. Remove the raviolini from the water with a slotted spoon, coat them with a little extra virgin olive oil to keep them from sticking, and use to garnish the bean soup.

Divide the soup among 6 warm bowls. Add 5 or 6 raviolini to each bowl and sprinkle the hazelnuts on top. Drizzle a little hazelnut oil over each bowl, add a spritz of lemon juice, and a tiny pinch of fleur de sel before garnishing with the celery leaves and shaved truffles, if using.

Make ahead: you can make the soup a couple days ahead of serving it.

Recipe adapted from Stir: Mixing it up in the Italian Tradition by Barbara Lynch, Barbara Lynch Gruppo