Put beans in a stock pot. Add extra virgin olive oil and flour. Stir mixture and cover. Add pork rind. Cover mixture with water. Cook for 1 1/2 hours over medium-low heat. Skim off impurities if necessary.
Saute onions, garlic, sage, rosemary and celery leaves in 1 tablespoon olive oil over low flame, about 10 minutes. Add them to pot of garbanzo beans after beans have cooked for 1 1/2 hours. Chop celery stalks and add to pot. Add potato, carrots, broccoli rabe, leeks and cabbage to pot. Simmer for 1 1/2 hours. Skim to remove impurities if necessary. Add additional water if soup is too thick. Soup is done when beans are tender and potatoes are no longer solid. Season with salt and pepper. Soup can be served with olive oil, toasted bread and Parmesan cheese if desired.