Calculate the cooking time. Allow 20 minutes per 450 g of ham.
Remove the outer wrappings and place ham in a saucepan. Cover with cold water, place the lid on top and bring to the boil.
Boil for the length of time you have calculated, or as indicated on the ham’s cooking instructions.
At the end of the cooking time, turn the heat off and leave the ham sitting in the hot water for about 10 minutes - this will make it easier to carve.
Drain off the water and place the ham on a baking tray.
Preheat the oven to 160°C / 320°F / Gas Mark 3.
Cover the ham on the baking tray with foil and roast for 30 minutes.
In a cup, mix up the honey with the wholegrain mustard.
Remove foil and spread over the surface of the ham using the back of a spoon or a knife.
Roast for a further 15 minutes until golden brown, basting once or twice during cooking with the honey glaze.