Bring a large saucepan of water to the boil. Reduce the heat and add the gammon and the cloves. Cover and simmer for 1 hr, topping up the water level when necessary.
Preheat the oven to 180C/160C fan-oven/Gas mark 4. Remove the gammon from the heat, drain and remove the skin. Place the ham, fat side up, on a rack in a roasting dish. Using a sharp knife, score the fat on the ham.
Mix 2 tbsp of redcurrant jelly with the mustard, then rub it into the scored skin. Cook in preheated oven for 1 1⁄2 hrs, or until cooked through.
About 5 mins before the end of the cooking time, put the remaining redcurrant jelly in a small pan with the Madeira and the citrus ring and juice. Warm gently over a low heat and simmer and stirring, for 5 mins.
Remove the gammon form the oven, transfer to serving plates and garnish with citrus slices.
Serve with the Madeira sauce, new potatoes, French beans and red cabbage.