1.Preheat oven to 180°C/160°C fan-forced.
2.Stir jelly, vinegar, sugar and cloves in medium saucepan over medium heat until sugar is dissolved. Reserve ¼ cup glaze for the onions.
3.Cut through rind about 10cm from shank end of leg in decorative pattern; run thumb around edge of rind just under skin to remove rind. Start pulling rind from widest edge of ham, continue to pull carefully away from fat up to decorative pattern; discard rind. (Reserved rind can be used to cover the cut surface of ham to keep it moist during storage.)
4.Using sharp knife, score fat by making shallow cuts diagonally in both directions at 3cm intervals to make a diamond pattern. Place ham on oiled wire rack in a large baking dish; pour in the water. Brush ham all over with glaze. Cover shank end with foil; roast, uncovered, 45 minutes.
5.Meanwhile, add onions to small baking dish with reserved ¼ cup glaze and 2 tablespoons water. Cover with foil; roast alongside ham for further 45 minutes or until tender. Brush ham with glaze every 30 minutes.
6.Serve ham with onions.
Check that oven is large enough to fit the ham. You can ask the butcher to remove the shank from the leg if necessary. Carved ham suitable to freeze for one month. Glaze suitable to microwave.Note