Season the pork with salt and pepper and sear in a heavy Dutch oven type pan (the interior should be a little bigger than the roast) preheated on a high heat. Once all sides of the pork have been nicely browned, remove and set aside. In the same pan, add the onion and apple and cook until soft and starting to caramelize. Pour the vinegar and cider over the onion and apple and reduce by half (if you wish to add sage or rosemary this would be a good time). Put the pork back in the pot and coat with the cider mixture. Place in a 350 degree oven and cook until fork tender, about an hour and a half to 2 hours. Remove from oven and let rest for at least twenty minutes. Remove the meat and slice against the grain to serve. If the liquid in the pan is not thick enough for your liking, return it to the stove top and thicken with a little corn starch.