Wash pork shoulder in water and vinegar ( optional) Pat dry, poke some holes all around the meat. In a bowl combine all the ingredients for pork and mix well to combine. Season well, but also ushing some of the seasonings in those holes you poked in the meat. Cover and marinade at least 4 hours, overnight is best.
Preheat oven to 375. Use a baking pan with a rack and lid. Pour ½ cup of hot water on the bottom of baking pan, add the pork shoulder on the rack, cover and bake for 1 hour, remove and baste with pan juices at the bottom of the pan , baste for 1,put back in the oven covered for another 1 hour and remove and baste again . Bake for 1 hour uncovered.
In the meantime, to make the balsamic glaze,
In a skillet add the olive oil and butter on low heat, add the ginger and garlic and stir well to combine, sauté for 2 minutes, then add all the other ingredients and cook slowly stirring constantly until it is thickened.
Remove pork from the oven and cut into desired sizes, drizzle glaze on top