To prepare the pulled pork, preheat the oven to 375°F.

Season the pork generously with salt and pepper. Place in a roasting pan just large enough to hold the meat. Roast uncovered for 2 hours, flipping the meat halfway through.

Remove the pan from the oven. Pour the water and vinegar over the pork and cover the pan with aluminum foil. Continue roasting for 1 hour more.

The pork is done when the meat is easily pierced with a fork. Pour off the fat and juices from the pan and place in a separate container. Skim the fat off the top and discard. Reserve the juices.

Using 2 forks, shred the pork and add to the reserved juices. Add the Tabasco sauce, adjust the seasoning with salt and mix well.

To prepare the pickled red onions, in a medium saucepan over high heat, combine the garlic, jalapeño, sugar, vinegar, salt, pepper and water. Bring to a boil, then add the onion and remove from the heat. Let stand until cool, about 1 hour. 

To prepare the sauce, in a small saucepan over medium heat, whisk together the mustard, garlic, vinegar and barbecue sauce. Simmer for 5 minutes, then remove from the heat. 

To serve, place a heaping tablespoon of the pulled pork on the bottom halves of the buns. Drizzle with the barbecue sauce and top with some of the pickled red onions. Cover with the top halves of the buns and serve.