Place oven rack on center level. Heat oven to 500 degrees.
Place the racks of lamb in a 14-by-12-by-2-inch roasting pan.
Whisk together the oil, mustard, rosemary, salt and pepper in a small bowl. Coat both sides of the racks with the mixture. Pat on a layer of bread or cracker crumbs.
Roast 20 minutes for rare. Let stand 5 minutes before carving.
Per serving: 646 calories, 67 gm protein, 2 gm carbohydrates, 39 gm fat, 221 mg cholesterol, 13 gm saturated fat, 466 mg sodium The Washington Post 0. 0.063157894736842