Preheat oven to 180˚C fan-forced. Meanwhile, using a sharp knife, score the ham fat (not the flesh) in a honeycomb pattern at 2 centimetre intervals. Insert a clove into the centre of each square of fat. Wrap the hock in foil (this prevents it from burning).
Place ham on a greased rack in a large baking pan lined with foil.
To make the glaze, combine all ingredients in a medium saucepan. Bring to the boil, stirring, over medium-high heat. Reduce heat and simmer, stirring occasionally, for 20 minutes or until reduced by a half.
Brush the ham fat a few times to evenly coat with the glaze. Roast, brushing with remaining glaze occasionally, for 1 hour or until ham is golden and caramelised. Set aside to cool for 30 minutes.