Slow Cooker BBQ Pulled Pork

1 medium onion, chopped
3/4 cup ketchup
1/3 cup cider vinegar
1/4 cup packed brown sugar
2 tablespoons paprika
1 teaspoon cayenne pepper
2 tablespoons Worcestershire sauce
2 tablespoons liquid smoke
3 teaspoons salt
2 teaspoons black pepper
2-3 pounds pork butt
Rolls or Buns
1 1/2 cups of your choice of barbecue sauce (or more if you like it extra saucy)

1. Combine all of the ingredients except the pork butt, salt and pepper, and the buns in a large slow cooker. Stir together with a spoon until well combined. Season the pork with salt and pepper on all sides. Add the pork and place the lid on the slow cooker. Cook for 8 hours on low or until pork is tender and easily pulls apart from the bone.

2. Take two forks and shred the pork. The pork and all the ingredients will form a very oily, fatty-looking juice. I drained this and got rid of it, then shredded the pork and put it back into the pot with barbecue sauce for about a half hour. Stir well and serve on rolls or buns.

Source: http://quickfeetgoodeats.com/slow-cooker-bbq-pulled-pork/