Place gammon ingredients in a large saucepan and cover with enough cold water to submerge the gammon (or alternatively use another liquid of your choice, like cider or ginger beer).
Bring to a simmer and cook over a gentle heat for 20 min per 500g, or until tender and cooked through –when the tip of a sharp knife slides into the meat easily it should be cooked.
Remove from heat and allow gammon to cool in cooking liquid.
Place the cooled gammon in a roasting tray and discard liquid.
Preheat oven to 200˚C.
To make the glaze, place all the ingredients in a saucepan and simmer gently for 30-40 minutes (adding a bit more water if necessary), until the nectarine breaks down completely.
Strain the jammy mixture through a sieve and discard the solids.
Using a sharp knife, carefully peel skin off the gammon, leaving a good layer of fat on the surface of the meat.
Score diamond- shapes into the fat.
Stud with cloves where the lines intersect (on the cross).
Brush gammon with glaze and roast for 20-30 minutes, basting with more glaze from time to time until dark golden and caramelised.
Allow to rest for 15 minutes before slicing and serving.