Place the ham, vegetables, peppercorns and bay leaf in a large saucepan. Cover with cold water. Place a lid on the saucepan, bring to the boil then reduce the heat and simmer for approx. three hours. Reserve the cooking liquid to use later. While the ham is cooking make the glaze. Place all the glaze ingredients into a saucepan and heat gently until sugar dissolves. Bring to the boil then simmer for a couple of minutes until the mixture becomes syrupy. Remove from the heat and set aside to let the flavours develop until the ham is ready. When the ham is cooked the skin will peel off easily. Preheat the oven to Gas Mark 6, 200°C (400°F). Remove the joint from the saucepan and place on a roasting tin. Using a sharp knife remove all the skin and score the fat into diamonds. Put a clove into the centre of each diamond. Remove the cinnamon stick from the glaze then brush the glaze over the ham. Add a ladleful of the reserved stock around the ham to keep it moist and bake for about 30 minutes until golden brown.