Place pork butt in slow cooker. Cover the pork with all the ingredients EXCEPT the lime and optional accompaniments. Place lid on top of slow cooker and cook on high for 6 hours or low for 8 hours.
Remove pork from slow cooker and shred into smaller pieces with two forks. Place the shredded pork back in slow cooker with the leftover sauce and sprinkle with the fresh lime juice. Stir well. Serve with optional accompaniments, if desired.
No slow cooker? Cook the pork in a oven! In an oiled Dutch oven over medium-heat heat, brown the pork roast on all sides. Push pork to one side, add the chopped onion and garlic and lightly brown, then add all remaining ingredients. Cover and cook it in a preheated 325F/163C oven for 2-3 hours.