From Andrea: "This soup makes me think of my childhood and how good our kitchen smelled when my mom made a batch of this stew. Delicious and farm-fresh to boot, this is the kind of meal you make when you’re homesick or just craving a little comfort."
Heat the oil in a large pot over medium. Add the sausage and brown it, stirring occasionally to break it into smaller pieces, 5 to 8 minutes. Stir in the leek, carrots, celery, potato, and garlic. Continue to cook until the vegetables soften up a bit and become fragrant, about 5 minutes. Add the bay leaves and stock, and bring the liquid to a boil. Reduce the heat and simmer for 30 minutes. Stir in the beans, kale, and a generous pinch each of salt and pepper. Continue to simmer the soup for an additional 15 minutes. Taste test and adjust seasonings as needed. Serve with grated Parmesan and some good-quality bread.