A recipe with Greek influence and ideal for spring as lamb meat is best during the spring season.
- Place onion, garlic, rosemary, lemon zest, apple cider vinegar, and olive oil into a food processor and pulse to combine.
- Sprinkle a generous amount of salt and pepper over the lamb. Place the onion marinade and lamb into a 1-gallon freezer bag. Spreading the marinade over all sides of the meat. Seal the bag and refrigerate for 1 to 2 hours
- After the 1-2 hours, remove lamb from the refrigerator and allow it to come to room temperature, around 20 minutes. When ready to grill, remove the lamb from marinade bag.
- Fat side down, place the lamb on the grill on the hot side of the grill
- Sear one side for 4 minutes, flip, sear the other side for an additional 4 minutes.
- ( if you are using a charcoal grill, move the lamb to the less hot side of the grill. Using a gas grill, lower your heat to low. Try to maintain a temperature of 300-350° F.)
- Cover grill and let cook for 35-45 minutes ,depending on thickness, meat thermometer inserted into the thickest part of the roast registers 130° F,for medium rare
- Place lamb on a cutting board with a well to catch the juices. Cover with foil and allow to rest for 5-10 minutes. Cut across the grain, 1/4 to 1/2 inch thick slices.
- Serve slices on a warm platter; pouring the meat juices over the slices.
To prepare grill. If you are using a charcoal grill, prepare the coals so that they are double layered on only one side of grill, and only sparsely single layered on the other side, called "banked" grilling.
Using a gas grill, heat the grill on high with all burners to start. After the initial browning you will reduce heat.