Trim off root end but do not separate stalks. Remove coarse outer stalks & leaves, sreserving leaves for garnis. Cut celery bunches crosswise once so bottom section is 5 inches long. Tie this bottom section with string into 4 sections & cut into 4 sections.
Pour broth into large skillet; add celery bundles. Cover; heat to boiling and cook about 15 minutes. Drain celery; place in shallow dish. Pour salad dressing over celery. Refrigerate 3 hours, turning bundles once or twice.
T0 serve, place a bundle cut side down on each plate. Remove string. Garnish with pimento strips and reserved celery leaves.