Soak the shank overnight, changing the water once. Soften the beans overnight in cold water.
Sweat the bacon, onion and garlic in a pan containing the olive oil until transparent. Add the meat and beans and just enough water to cover the ingredients. Season with the bay leaf, saffron, paprika and pepper.
Bring to a boil and simmer on medium heat for around 1 1/2 hours. Stir several times during cooking and add more water if necessary. When the beans are almost soft, add the sausages. Adjust the seasoning and leave to simmer until the beans are completely soft.
Before serving, remove the meat and sausage from the pan, cut it into pieces and combine with the beans.