Step 1Heat the oven to 450 degrees. Season the lamb with salt and pepper and let it rest until it reaches room temperature, about 30 minutes. Place in a roasting pan and roast for about 20 to 25 minutes for medium-rare.
Step 2When the lamb has cooked for about 15 minutes, mince the mint, garlic and lemon zest until very fine, almost a paste. Fresh mint will discolor almost immediately, so do this at the last minute, about 5 minutes before you'll use it.
Step 3Spread the mint gremolata over the rack of lamb and return to the oven for the final 5 minutes.
Step 4Remove the rack and let it rest under a foil tent for about 10 minutes. Cut it into chops and serve, two chops per person.