Cut roast in half; place in a 4- or 5-qt. slow cooker. In a small bowl, mix water, bouillon granules and seasonings; pour over meat., Cook, covered, on low 6-8 hours or until tender. Remove beef; cool slightly. Meanwhile, skim fat from the cooking liquid., Shred meat with two forks; return to slow cooker. Using a slotted spoon, place meat on bun bottoms. Replace tops. Serve with additional cooking liquid on the side.