If your lamb rack doesn't come already frenched (with rib bones exposed), use a sharp knife and cut the meat and tendons away from the bones along the top of the ribs; this is mostly for show — we often just cook the racks as-is and the tougher meat near the bone either gets put in the compost pile or made into stock (whatever you do, don't waste it — Fido would love it)
Cut the lamb with a sharp knife between the vertebrae so that you now have two evenly sized racks. Salt the lamb.
Combine the allspice berries, lavender, coriander, cinnamon stick, peppercorns and cumin in a spice grinder or (cleaned out) coffee grinder and make into powder. I had to help pre-break the cinnamon stick into many small pieces. Mash the garlic with a mortar and pestle or the side of a knife with some salt on a cutting board to make into a paste. Grate or zest the lemon rind just until you get to the white part all the way around. Combine all of your ground and pureed spices.
Spread the spice mixture all over the lamb and let sit for 10 min. You could prepare the recipe to this point and let the rub sit on the lamb overnight, but it needs at least a few min for the meat to absorb some of the flavors.
Heat a grill or large cast-iron pan with a dollop of lard over medium-high heat. Prepare a roasting rack or cooling rack over a baking sheet. Sear the lamb on both sides. Transfer to a prepared rack. If the bones are frenched, wrap just them in aluminum foil, but leave the meat exposed. Top the meat with the bay leaves and thyme sprigs.
Roast the lamb rack in the oven until the internal temperature is 130 degrees for rare or 135 for medium-rare or 140 for medium. The lamb is going to continue to cook while it rests, an important step.
Tent the lamb with aluminum foil and let rest for 10-15 min, covered. Remove the aluminum foil and bay leaves and thyme sprigs and compost the plants. (If you used dried thyme, brush off gently, leaving the rub from earlier.) Cut the lamb chops between the ribs, finding the opening between the joint. Garnish with the fresh mint. Serve with roasted vegetables and a glass of dry red wine.