Step 1 If the lamb has been tied into a roll, untie it and lay it flat, skin-side down. There will be a range of thicknesses to the meat, with some areas fairly thin and some very thick. Slice partway through the thickest portions to allow the meat to lie flat.
Step 2 Slice the garlic into thin slivers. Turn the lamb over so that the skin side is facing up. Use a paring knife to cut slits all over the skin side roughly a half-inch deep and a half-inch apart. Stuff a garlic sliver into each slit (it's easiest if you use the tip of the knife to hold the slit open; don't worry about everything being perfectly neat).
Step 3Sprinkle both sides of the meat with salt and pepper and place it in a zip-lock bag. Pour the wine over the lamb, press out all the air and refrigerate for at least a couple of hours to marinate.
Step 4When you're ready to cook, soak about 2 cups of wood chips in water to cover. Light the coals and when the coals are glowing hot, empty them into one side of the grill, banked against the side. Drain the wood chips and place on top of the coals.
Step 5Pat the lamb dry with a paper towel and place it skin-side down over the hottest part of the fire. Sear the lamb 3 to 5 minutes per side, until browned.
Step 6Turn the meat again and move it to a cooler part of the grill and cover. Cook 10 minutes on one side, turn and cook about another 10 minutes, until a thermometer inserted into a thick part of the meat reads 115 degrees. That makes about 30 minutes cooking total. After allowing the lamb to rest, this will give you a range of doneness from medium-rare to medium.
Step 7Remove the meat from the grill and set aside 10 minutes to rest before carving against the grain. Serve with tapenade on the side.