Rolling the lamb around the filling means you get some of those bright flavors in just about every bite. For the best flavor, stuff the lamb the day before you roast it. Garnish the platter of lamb with some of the same herbs from the filling, if you like.
1/3 cup small-diced dried apricots
3 medium cloves garlic, peeled
1 cup loosely packed fresh flat-leaf parsley leaves
1/2 cup loosely packed fresh mint leaves
1 Tbs. chopped fresh rosemary
1 Tbs. Dijon mustard
Kosher salt and freshly ground black pepper
3 Tbs. extra-virgin olive oil
1 3-1/2- to 4-1/2-lb. boneless leg of lamb
1 cup lower-salt chicken broth
1/4 cup dry white wine or dry vermouth
In a small bowl, cover the apricots with 1/4 cup boiling water; let soak for 5 minutes.
Meanwhile, pulse the garlic, parsley, mint, rosemary, mustard, 3/4 tsp. salt, and 1/4 tsp. black pepper in a food processor until coarsely chopped. With the machine running, add the olive oil, and process to a thick paste. Drain the apricots and stir them in.
Lay the meat flat and pat dry with paper towels. Trim any excess fat. If there are portions that are much thicker than others, butterfly the thicker portions of the lamb to make it evenly thick. Lightly pound the lamb with a meat mallet, if necessary, to further even it out and make it roughly rectangular in shape. Season lightly with salt and pepper.
Spread the herb paste over the lamb, using your fingers to work it into any crevices. Starting at one short end, roll the lamb up tightly, making sure to roll the meat so slices will cut across the grain. Tie the roll snugly at 1-inch intervals with kitchen twine. For a more compact shape, tie the roast lengthwise with a piece of twine. If there is any herb paste left on the work surface, rub it on the outside of the lamb. Wrap the lamb well in plastic wrap and refrigerate for at least 8 and up to 24 hours.
Let the lamb sit at room temperature for about 1 hour before roasting. Meanwhile, position a rack in the center of the oven and heat the oven to 350°F.
Unwrap the lamb, transfer it to a small, flameproof roasting pan, and roast until an instant-read thermometer inserted into the center of the meat reads 125°F to 135°F for medium rare, 45 minutes to 1-1/4 hours; begin checking early. Transfer to a cutting board, tent with foil, and let rest for 20 to 30 minutes.
Meanwhile, add the chicken broth and wine to the roasting pan. Simmer over medium heat, scraping up any pan drippings and stirring frequently, until slightly reduced, about 4 minutes.
Cut the lamb into 1/2-inch-thick slices, snipping away the twine as you go, and transfer to a platter. Add any juice from the cutting board to the roasting pan. Strain the jus, and season to taste with salt and pepper. Serve the lamb with the jus.