Place pork in a medium roasting pan. Stir together the stock, vinegar, BBQ sauce, jalapenos, onion, and garlic in a bowl. Pour the mixture over the pork and season with salt and pepper. Cover the pan with foil and cook in the oven or on the grill for 3 1/2 to 4 hours or until the meat is fork tender. Let cool in the braising liquid, then drain the liquid from the meat and shred the meat into bite-sized pieces. Serve on buns, drizzled with Black Pepper Vinaigrette.
Black Pepper Vinaigrette:
1/2 cup rice vinegar
1 heaping tablespoon Dijon mustard
1/4 teaspoon salt
1/2 teaspoon coarsely ground black pepper
2 teaspoons honey
3/4 cup extra-virgin olive oil
Whisk together the vinegar, mustard, salt, pepper, and honey until combined. Slowly whisk in the oil until emulsified. Set aside until ready to use.