Buy a boneless leg of lamb and if it comes already tied, remove the strings so you can cut away the excess fat, stud the inside with garlic, and season it with salt and pepper. Let the lamb sit at room temperature for half an hour before you roast it. These cooking times are approximate; use an instant-read meat thermometer to test the internal temperature. If the lamb is done before you need it, cover it loosely with foil and let it rest in a warm place.
|1||boneless leg of lamb (5 to 6 pounds)|
|5||cloves garlic, cut into slivers|
|Salt and pepper, to taste|
|2||sprigs fresh rosemary, leaves chopped|
|4||carrots, cut on the diagonal|
|2||leeks (white part with some of the light green) well rinsed and cut on the diagonal|
|2||large yellow or red onions, each cut into 8 wedges|
|5||sweet potatoes, peeled and cut into large wedges|
|Olive oil (for sprinkling)|
|Handful fresh flat-leaf parsley, chopped|
|1||bunch watercress or arugula, stems removed|
1. Set the oven at 450 degrees. Have on hand a baking dish and a large roasting pan.
2. Trim off most of the outside fat from the lamb, leaving a little on to keep the meat moist. With a small knife, make slits on the inside and outside of the meat. Insert the garlic slivers into the slits. Sprinkle with salt and pepper and rosemary on the inside and drizzle with oil. Roll the meat into a tight cylinder. Tie with kitchen twine at 1-inch intervals and around the ends of the roll to make a tight package. You should have a slightly oval shape, which will be easier to slice into rounds.
3. Place rolled leg in the baking dish. Sprinkle with oil, salt, and pepper. Place in the middle of the oven. Roast for 20 minutes.
4. Lower the oven temperature to 325 degrees and continue roasting for 50 to 90 minutes, depending on the size of the leg. For rare meat, the cooking time is about 10 to 13 minutes per pound (an instant-read meat thermometer will register 125 to 130 degrees). For medium to well-done meat, cook the lamb for 13 to 15 minutes per pound (the temperature is 145 to 160 degrees). The meat continues to cook for a few minutes when it rests outside the oven in a warm place.
5. Meanwhile, in a bowl, combine the carrots, leeks, onions, and sweet potatoes. Sprinkle with olive oil, salt, and pepper. Toss well. Spread the vegetables on the roasting pan. Roast the vegetables for 1 hour, turning several times, until they are tender and beginning to brown at the edges.
6. When the lamb is cooked, remove it from oven, cover lightly with foil, set aside in a warm place for 15 minutes.
7. Remove foil and twine. Carve the lamb at a slight diagonal into 1/3-inch slices. Place the meat in overlapping slices in the center of a warm platter. Surround it with roasted vegetables. Drizzle the meat with the pan juices. Sprinkle with rosemary and parsley. Garnish with watercress or arugula.