In a large saucepan, combine the first 8 ingredients; if desired, stir in liquid smoke. Bring to a boil over medium-high heat. Reduce heat; simmer, uncovered, 5 minutes, stirring occasionally., Place ham in a 5- or 6-qt. slow cooker. Add sauce; stir gently to combine. Cook, covered, on low 2-3 hours or until heated through. Serve on rolls. Top with pepperoncini if desired.