Heat the olive oil in a soup pot over medium heat. Add the carrots, celery, onions, potatoes, and some salt and pepper and saute for 10 minutes. Pour in the chicken stock. Add the oregano and cherry tomatoes and simmer for 20 minutes. Add the zucchini and beans and simmer for another 15 minutes. Remove from the heat.
Ladle into a big bowl and top with pesto, if using, and Parmesan. Serve with Italian bread.