This is incredibly easy to do with only two ingredients. Rather than wasteing the apple juice after cooking the gammon (ham) why not use it as a base of a home made apple sauce or dressing sauce for the meat.
Gammon is from an Old Northern French word "Gambe" for hind- leg of the pig or ham. Historically gammon refers to cured whole sides of pork but in recent times the word gammon is used mostly for the hams. If you cannot get gammon a normal leg of ham will work just as well.