3. Make the soup and serve: Heat oil in an 8-qt. saucepan over medium. Cook rosemary, lardo, bay leaf, carrot, and onion until vegetables are soft, 4-6 minutes. Increase heat to medium-high and add wine; cook until reduced by half, 1-2 minutes. Add stock, beans, parsley, and 2 cups water; boil. Reduce heat to medium; cook, covered, until beans are tender, 1½-2 hours. Add reserved gnocchi, the parmesan, butter, and tomato purée; simmer until gnocchi are cooked through, about 15 minutes. Discard bay leaf. Ladle soup into bowls; garnish with reserved pesto and more parmesan.