To make the glaze, place honey into a medium saucepan and bring to the boil over medium heat. Reduce heat and simmer for 5 minutes (the mixture will bubble so keep an eye on it while it is on the heat) or until deep golden. Remove from heat and stir in brown sugar, orange juice and whiskey. Return to heat and simmer, stirring often, for 10 minutes. Remove from heat and set aside to cool for 45 minutes or until syrupy.
Preheat oven to 160˚C. Using a sharp knife, score the ham fat (not the flesh) crossways at 2 centimetre intervals. Wrap the hock in foil to prevent burning.
Place ham on a greased rack in a large baking dish lined with foil.
Brush the ham fat a few times to evenly coat with the glaze. Bake, for 50 minutes, brushing with remaining glaze occasionally, or until ham is golden and caramelised.