If you have time, it is worth soaking the ham in cold water overnight to remove excess salt.
5-6 kg/10-12lb good-quality ham, ideally left on the bone
1 tsp black peppercorns
5 fresh bay leaves
2 sticks of celery, chopped
1 yellow onion, chopped
4 carrots, roughly chopped
For the glaze
2 tbsp Dijon mustard
3 tbsp soft brown sugar, such as muscavado
Finely grated zest and juice of one orange
150ml/5oz white wine
A handful of cloves
Place the ham into a large pot and add the peppercorns, bay leaves and vegetables. Pour over enough water to cover and cover with a firm-fitting lid. Bring to the boil then immediately turn down the heat. Simmer the ham gently for three-and-a-half hours, topping up with water as necessary. When the ham is cooked, the meat will be firm. Remove the pot from the heat and leave the ham to cool in the cooking broth.
Now heat the oven to 180C/350F/Gas4.
To make the glaze, simply mix the mustard, sugar, orange juice and zest and wine together until you have a loose paste.
Remove the skin from the ham, leaving as much fat on as possible, score it evenly all over, and stud each diamond shape with a clove. Using a pastry brush, brush half the glaze evenly over the outside of the ham. Place in a baking tray on the middle shelf of the oven. Roast for 10 minutes then brush the rest of the glaze on top. Cook for 20 minutes or until sticky, golden brown and slightly set. Serve with mustard and cranberry sauce alongside.