Rinse and sort the dried beans, removing any small stones or damaged beans. Cover them generously with water and soak overnight for 8 hours, then drain and rinse before cooking.

For a quick soak, place the beans in a pot of water and boil for 2 minutes. Remove the pot from the heat, cover, let the beans stand for 1 hour, then drain and rinse.

Add the soaked beans, broth or water, ham hock, onion, carrots, celery, garlic, bay leaf, thyme, and black pepper to a large Dutch oven or soup pot. Stir gently to distribute the vegetables and seasonings.

Bring the mixture to a boil, then reduce the heat to a gentle simmer. Cover the pot partially and cook for 1½–2½ hours, stirring occasionally, until the beans are completely tender.

Remove the ham hock and bay leaf from the pot. Pull the ham meat from the bone, chop or shred it, and return the meat to the soup.

Taste the soup only after the ham and beans are fully cooked, then add the salt if necessary. Stir in the chopped parsley just before serving, and add a little water or broth if the soup is thicker than desired.