For the gammon: Place the gammon into a large pot with the chicken stock. Add water to cover. Add the carrots, celery, garlic, ginger, peppercorns, thyme, rosemary and bay leaves. Bring to a boil, then reduce heat and simmer until tender, 2 1/2 to 3 hours. Remove the gammon from the stock and let cool slightly.
Preheat the oven to 200 degrees C (400 degrees F).
For the glaze: Mix together the soy sauce, honey, orange juice, ginger and garlic in a bowl. Slit open the chile, remove just a few of the seeds and add them to the glaze; discard the chile.
Place the gammon in a roasting pan. Lightly score the fat and cover with the glaze. Roast until sticky and crisp around the edges, 20 to 30 minutes.