1.Melt butter in a large casserole over medium heat. Add onions and garlic and sauté. Add the beer, chicken or beef bouillon, 1/3 cup of maple syrup, mustard, spices and pepper. Mix well to blend the mustard in and bring to a boil.
2.Place the pork in the casserole. Bring to a boil, cover and let simmer for 1 ½ hours or until the meat is tender.
3.Preheat the oven to 200ºC (400ºF).
4.Remove the pork from the casserole; remove the string from around the shoulder (remove the skin and trim off some fat, if desired) and place in an oven-proof dish.
5.Cook the bouillon mixture until it is reduced by half. Add the remaining (60 ml) maple syrup.
6.Baste the meat with bouillon and place in the oven for 15 to 20 minutes. Baste frequently.
7.Carve the pork and serve with your choice of vegetables.