01 - Preheat the oven to 425°F. Pat the racks of lamb completely dry with paper towels to ensure proper searing.
02 - In a small bowl, thoroughly combine garlic, rosemary, thyme, parsley, salt, pepper, olive oil, and Dijon mustard until a thick, uniform paste forms.
03 - Rub the herb paste generously over the entire surface of both lamb racks, pressing firmly to adhere the mixture to the meat.
04 - Place the racks on a roasting rack set in a roasting pan, fat side up. Let stand at room temperature for 15 minutes to allow the flavors to penetrate.
05 - Roast in the preheated oven for 20–25 minutes for medium-rare (internal temperature 135°F), adjusting time for desired doneness.
06 - Remove from the oven, tent loosely with aluminum foil, and let rest for 10 minutes to allow juices to redistribute throughout the meat.
07 - Slice the racks into individual chops between the bones. Arrange on a serving platter and accompany with mint jelly. Garnish with fresh mint leaves if desired.