1) For the ham: Preheat oven to 150C/Gas 2. Place ham in a roasting pan and pour about 180ml water into the bottom of pan. Cover with aluminium foil and bake for 1 hr and 40 mins or until heated through, soft and tender.
2) For the glaze: Whisk all ingredients together in a saucepan until smooth and heat over medium-low to medium heat until simmering. Simmer for 2 mins and remove from heat.
3) When ham is heated through, remove the aluminium foil, and pour or brush the glaze over the top to cover completely. Raise oven temperature to 200C/Gas 6.
4) Return the ham to the oven and cook, uncovered, for 20 mins or until glaze is caramelised and bubbly. Let rest for 10 mins before slicing. Serve with desired fixings.