01 - Preheat the oven to 425°F. Pat the racks of lamb dry with paper towels.
02 - In a small bowl, combine garlic, rosemary, thyme, parsley, salt, pepper, olive oil, and Dijon mustard to form a thick paste.
03 - Rub the herb paste generously over the entire surface of the lamb racks.
04 - Place the racks, fat side up, on a roasting rack set in a roasting pan. Let stand at room temperature for 15 minutes to marinate.
05 - Roast the lamb in the preheated oven for 20–25 minutes for medium-rare (internal temperature 135°F), or until desired doneness.
06 - Remove from the oven, tent loosely with foil, and let rest for 10 minutes.
07 - Slice the racks into individual chops and arrange on a serving platter. Serve with mint jelly and garnish with fresh mint leaves if desired.