Ham and Mustard Greens Clay-Pot Casserole

This is another nostalgic recipe making a comeback in Hong Kong. Most of its residents were once peasants or are of peasant stock, and this dish is redolent of the family hearth with its traditional clay pot simmering away, wafting its promise of hearty, nutritious meals. It is really quite good, and one can see why, apart from nostalgia, it remains popular. The few slices of ham judiciously introduced are enough to flavour and add some substance to this mainly vegetable casserole. Serve it