Bring to the boil & reduce to a simmer with the lid on. Cook for 45 minutes per kilo, and turn the gammon half way through cooking.
Remove to a board, and cut off the string and the rind, leaving the fat attached. Score the fat on a diagonal cross hatch and prepare the glaze.
Take 2 ladles of the cooking liquor and the juice of 2 more apples. Reduce until it resembles a thick caramel, and pour over 2 heaped teaspoons of grainy mustard. Mix well and baste all over the ham.
Get the ham into the oven at 180c and let it brown, baste again and roast till caramelised and golden. Let it cool before carving.
For a delicious sandwich, mix the remainder of the mustard caramel with mayonnaise and a squeeze of lemon juice - total flavour bomb.
