In stockpot, heat olive oil. Add onion and saute for 4-5 minutes on medium heat. Add garlic and saute for 1 minute.
Add carrots, celery and potatoes. Cook over low heat for 5 minutes.
Add tomatoes, Swiss chard, sage and salt. Cover and simmer for over medium low heat for 20 minutes until greens are wilted and tender.
Add water and Parmesan rind and simmer on low for 40 minutes.
Add in beans, cook for 10 minutes. Preheat oven to 350 degrees.
Place bread in base of a casserole dish. Remove Parmesan rind (if it hasn't dissolved) from soup. Ladle soup on top. Cook for 10 minutes.
Remove from oven and drizzle with olive oil.