Bring ham hock to the boil in 5 litres of water. Reduce heat and simmer for 1 hour. Remove hock and stand to cool and strain and reserve stock. Remove meat from the bone and dice.
Heat oil in a large saucepan and fry prosciutto till crisp.
Add lettuces, beetroot, tomato paste and 3 litres of reserved stock. Simmer for 30 minutes until beetroot is tender, then add meat and beans. Cook for a further 5 minutes until meat and beans are warmed through. Stir through dill.