Preheat oven to 180C/355F/Gas 4.
Using a small sharp knife, cut through the rind around the shank of the ham. Carefully lift the rind from the fat in one piece, running your fingers through where the rind and fat are joined to ease away. Reserve the rind and use to cover the cut ham when storing.
Score the white fat in a diamond pattern and press star anise into the centre of every second or third scored diamond.
Place the ham on a rack over a roasting tray, then pour a small amount of water into the base of the roasting tray to prevent the glaze from burning.
Place the remaining ham ingredients into a saucepan over low heat, stirring until the sugar has completely dissolved.
Remove the glaze mixture from the heat and carefully pour over the ham making sure that all of the exposed fat is covered.
Transfer the ham to the oven to bake for 30-40 minutes, basting occasionally, until the ham is golden all over.
Remove the ham from the oven and place it onto a large platter ready to carve.
For the lemon potato salad, bring a large saucepan of water to the boil then add the potatoes and salt. Reduce the heat and simmer for about 8-10 minutes, until the potatoes are tender when pierced with a knife. Remember to undercook the potatoes a little, because they will continue cooking in their own heat and steam when removed from the water.
Place the olive oil, lemon juice and sumac into a bowl, stir to combine and season, to taste, with salt and freshly ground black pepper.
Pour half of the sumac dressing over the hot potatoes and stir very gently. Leave to cool, then add the capsicum, chilli, mint, parsley, spring onion and remaining dressing and stir gently to combine.
To serve, place several slices of ham onto each plate with a large spoonful of potato salad alongside.