Buy a pre-cooked ham on the bone. Allow plenty of time for the preparation – it is not difficult but it is a little messy. Strip off the brown skin, trying not to disturb the layer of creamy fat beneath it. Score the surface of the fat into small diamonds and stud each diamond with a clove. Line a large roasting pan with a double thickness of aluminium foil, bringing the foil over the edges of the pan. (This will catch drips of glaze falling off the ham and prevent flare-ups. It also means a clean roasting pan at the end of cooking time.) Put the ham in the pan, making sure the foil stays upright.
Preheat the oven to 225°C. Mix the glaze ingredients together, pour over the ham and put it in the oven. If you are glazing for appearance only, it will take about 45 minutes. As parts of the fat take on enough colour, a rich golden brown with slightly charred edges, place small pieces of foil on top to deflect the heat. If you want to serve the ham hot, allow an hour longer for it to heat through (about 1 1/2 – 1 3/4 hours in total), but lower the heat to 200°C after 1 hour. (You may need to protect the entire surface of the ham with foil after 50–60 minutes. The ham should be basted with the glaze every 20 minutes or so.)
Serve the ham hot or at room temperature. Use a long, thin-bladed knife to slice it. Cut the first slice vertically, down to the bone, in the centre of the leg, then slice at a slight angle on either side of this cut. This gives every slice of ham (until you get closer to the bone) a rim of glaze-encrusted fat.