1/2 cup fine, dry breadcrumbs  | 
                                                2 teaspoons dried whole dillweed  | 
                                                1/2 teaspoon garlic powder  | 
                                                1/4 teaspoon pepper  | 
                                                8 (3-ounce) lean lamb loin chops (3/4 inch thick)  | 
                                                3 tablespoons hot-sweet mustard  | 
                                                3 tablespoons cider vinegar  | 
                                                vegetable cooking spray  | 
                                                1/2 cup seedless green grapes, quartered  | 
                                                1/2 cup seedless red grapes, quartered  |