Heat the canola oil in a large soup pot over medium heat. Add the sausage, leeks and garlic and cook 3-5 minutes. Add the carrots, celery, cabbage, tomatoes, squash, herbs, beans, broth, water, salt and pepper. Bring to a boil, then reduce heat to low and simmer for 30 minutes. Add the tortellini and cook 8 minutes (or according to package instructions). Stir in the parsley, and ladle into bowls, topped with basil chiffonade and Romano.