Boil gammon: Put gammon, onions, carrots, bay leaves, and peppercorns in a pot. Cover with apple juice/ginger ale. Simmer 20 min per 500g until cooked.
Glaze: Heat jam, mustard, sugar, vinegar, and cloves in a small pot until sticky.
Roast: Precaliente el horno a 200°C. Remove skin, score fat, brush with glaze. Roast 20–30 min, basting once or twice.
Sirve: Slice thick. Enjoy warm or cold.