Ingredients
½onion
4clovesgarlic,peeled
2tbspfresh rosemary leaves,or 1 tbsp dried
1zest of lemon
1tbspapple cider vinegar
2tbspextra virgin olive oil
kosher salt and freshly ground black pepper
6lbsboneless leg of lamb,butterflied
Preparation
Put onion, garlic, rosemary, lemon zest, apple cider vinegar, and olive oil into a food processor and pulse to combine. (Or just chop the onions, garlic, and rosemary very well and combine with the rest.)
Sprinkle a generous amount of salt and pepper over the lamb. Place marinade and lamb into a 1-gallon freezer bag. Spread marinade over all sides of the meat.
Seal the bag and refrigerate for 1 to 2 hours.
Remove lamb from refrigerator and let come to room temperature (about 20 minutes). When ready to put on the grill, remove it from the marinade bag.
To help make the lamb easier to turn on the grill, insert a couple of skewers crosswise through the lamb.
If using a charcoal grill, prepare the coals so that they are double layered on one side of the grill, and sparsely single-layered on the other side of the grill (this is called “banked” grilling).
If using a gas grill, heat the grill on high on all burners to start. After the initial browning, reduce the heat.
Place the lamb, fat side down, on the grill on the hot side (double layer charcoals). Be prepared with a squirt bottle of water or a couple of cups of water (if using a charcoal grill) to control the flames if needed.
Sear one side for 4 minutes, then flip the lamb over to sear the other side for another 4 minutes.
If using a charcoal grill, move the roast to the less hot side of the grill. If using a gas grill, lower the heat to low. Maintain a temperature of 300 to 350 degrees F.
Cover the grill and let cook for an additional 35 to 45 minutes (depending on how thick and how many pounds the roast is) until a meat thermometer inserted into the thickest part of the roast registers 120 degrees F for rare or 130 degrees F for medium-rare.
Transfer to a cutting board with a well to catch the juices. Cover with aluminum foil and let rest for 5 to 10 minutes. Remove the skewers if using any.
Cut across the grain, ¼ to ½-inch thick slices. Serve slices on a warm platter; pour meat juices over the slices. Serve with mint jelly or horseradish.
