Preheat the oven to 140°C.
Score the ham fat into diamonds, stud with cloves, and place on a tray rack.
Bake ham for one hour, basting with honey every 10 minutes.
Sprinkle with orange zest, cover with foil, and rest for 30 minutes.
Preheat the oven to 200°C for the vegetables.
Heat vegetable oil in a large roasting tin in the oven.
Parboil potatoes for 5-10 minutes, then drain and steam dry.
Roast potatoes in hot oil for 40-50 minutes until golden.
Parboil carrots and parsnips until tender and drain.
Fry carrots and parsnips in oil, adding honey to caramelise them.
Sauté chestnuts in butter, then stir in sprout tops and seasoning.
Carve the ham and serve with prepared vegetables and gravy.