bone, bay leaf, parsley, onion. Bring to a boil, then lower heat, partially cover, and let simmer very gently until the beans are tender. Add more water if needed. Remove and discard bay leaf. Remove ham bone, cut off all meat, and return it to the pot. Remove about 1 cup of the beans and a little bean liquid. Mash to a paste and stir this into the pot to thicken soup. Add salt and pepper to taste. If desired, thin soup with milk.