Place the ham on a wire rack in a roasting tin, fat side up. Cover with foil and bake 1/2 hour per kilo. Meanwhile, mix together the honey, mustard powder and ground cloves.
About 20 minutes before the ham is done, remove from the oven. Remove any skin from the ham. Score the ham in a diamond pattern with a sharp knife and insert a whole clove into each diamond. Brush all over with the honey-mustard mixture. Bake, uncovered, 20 more minutes. Remove from the oven and let rest 10 minutes before slicing.