Preheat broiler. Trim fat from chops. Season chops and zucchini with salt and pepper. Arrange chops and zucchini, cut sides down, on the unheated rack of a broiler pan. In a small bowl stir together mustard, honey, and rosemary. Brush some of the mustard mixture on top of the chops.
Broil chops and zucchini 3 to 4 inches from the heat for 5 minutes. Turn chops and zucchini; brush remaining mustard mixture on the chops and zucchini. Broil for 5 to 10 minutes more or until lamb is medium doneness (160 degrees F) and zucchini is tender.