In a small bowl, using a potato masher or using a small food processor, coarsely purée ½ cup of the beans with ½ cup of water or stock and set aside.
To a large pot set over medium heat, add the oil, onion, bay leaf, garlic ,celery root, carrots, leeks, and fennel and cook, stirring occasionally, until the vegetables have softened slightly and are beginning to brown, about 15 minutes.
Add the zucchini, squash, rutabaga, parmesan rind and sauté.
Stir in the puréed and whole beans, the tomato paste, and 4-5 cups of stock and season with salt and black pepper to taste. Turn the heat to low and continue cooking, adding hot water as needed to maintain a thick, soupy texture, until the vegetables are fully soft, about 25-30 minutes.
Divide evenly among 4-6 bowls and drizzle with olive oil if desired. Serve with bread, grated parmesan cheese and or fried egg.