I would cook the beans a while before adding the vegetables just to make sure the beans will be tender (I had a bad experience with white beans that never got tender!). I would also substitute 4 cups water with 4 cups chicken stock.
1 cup white beans
10 cups water, more if needed
2 large onions, chopped
1 pound kale, chopped
2 potatoes, peeled and cubed
1 6-ounce can tomato paste
1 teaspoon vinegar
4 garlic cloves, minced
chorizo or sausage chunks (optional: for the non-vegetarian)
salt and pepper to taste
Soak the beans overnight. Rinse in cold water. Pour the water into a large soup pot and bring it to a boil. Add the beans, onions, kale, potatoes, tomato paste, vinegar, chorizo and garlic. Cook slowly over low-medium heat for 2 hours. Add more water if necessary. Stir from time to time so the soup does not burn on the bottom of the pot. When the soup is done, add the seasonings and stir the soup well. Turn off the heat, cover the soup pot, and let it stand for 10 minutes before serving. Serve hot.
Twelve Months of Monastery Soups by Brother Victor-Antoine d’Avila-Latourrette