Bring the water to the boil in a tall pan. Add the ham, reduce to a low heat and cook at just below the boil for approx. 1 hr.
Cover the beans with water, add the thyme, bring to the boil, cover and cook for approx. 30 mins. until just soft. Set aside approx. 100 ml of cooking water, drain the beans, remove the thyme. Heat the butter in a pan. Sauté the shallot, add the beans and reserved cooking water, simmer for approx. 5 mins., season.
Ginger & mustard sauce
Mix the mustard with all the other ingredients up to and including the lemon juice. Cut the smoked ham into slices. Serve with the beans and ginger & mustard sauce.