Place the sliced onion and minced garlic in the bottom of the slow cooker to create a base layer.
Set the pork shoulder on top of the onions and garlic.
In a mixing bowl, combine the bourbon, brown sugar, barbecue sauce, apple cider vinegar, smoked paprika, salt, and black pepper.
Pour the sauce mixture evenly over the pork.
Cover and cook on low for 8 hours until the pork is very tender.
Remove the pork from the slow cooker and shred it with two forks, discarding any large pieces of fat.
Return the shredded pork to the slow cooker and stir it into the sauce to coat evenly.
Serve the pulled pork on soft rolls.