With a knife, remove the skin, the ears and the muzzle from the deer head. Put the head, the vegetables and the herbs in a large pot. Fill with cold water and bring to boil. Cook for 3 hours or until the meat separates from the bone.
Preheat oven to 350°F.
Put the head in a large iron-cast saucepan and cover with BBQ sauce. Cook in the oven at 350°F for 30 to 40 minutes and baste regularly with the sauce. Add water if necessary.
Sear the onions and the garlic in butter. Deglaze with whisky. Add maple syrup and reduce by 2/3. Add beer, ketchup, apple juice, Worcestershire sauce, HP sauce, chilli powder, pepper and chilli pepper. Cook for one hour over low heat. Add mustard and concentrated meat stock. Stir well.