Tie a piece of string around each piece of pork to maintain a nice shape while cooking. In a large pot sear off pork shoulder (season liberally first). Add vegetables and herbs after meat is browned, add liquids and bring to a boil. Season and place in a 350° oven to braise. Should take 2-3 hours.
Place potatoes in a large pot, add cold water to cover and season aggressively with salt. Bring to a boil and cook till potatoes are tender. Drain potatoes, mash while still hot with rest of the ingredients, season and reserve.