- 1 (4 pound) boneless leg of lamb, trimmed of fat
- 1 teaspoon toasted sesame oil
- 1 tablespoon chopped fresh rosemary
- 1 teaspoon kosher salt
- 1/2 teaspoon freshly ground pepper
- 1/3 cup apricot preserves
- 2 tablespoons balsamic vinegar, divided
- 3/4 cup apricot nectar
- 2 teaspoons cornstarch
- Preheat oven to 425 degrees F. Coat a roasting pan with cooking spray.
- Make several shallow diagonal cuts in lamb; tie kitchen string around it in 5 places (see Tip). Rub oil then rosemary, salt and pepper all over the lamb and into the cuts; transfer to the prepared pan.
- Roast the lamb for 20 minutes. Reduce heat to 375 degrees F and turn the meat over. Continue roasting for 40 minutes more.
- Combine apricot preserves and 1 tablespoon vinegar in a small bowl. Remove the roast from the oven, spread the preserves mixture on it and pour apricot nectar into the pan. Continue roasting until a thermometer inserted into the thickest part registers 140 degrees F for medium-rare, 15 to 25 minutes more. Transfer to a cutting board and let rest for 10 to 15 minutes.
- Meanwhile, whisk the remaining 1 tablespoon vinegar and cornstarch in a small bowl until combined. Skim any fat from the pan juices. Add the cornstarch mixture plus any accumulated juices from the roast to the roasting pan. Place the pan on the stovetop and boil over medium-high heat, whisking constantly, until the sauce thickens, 1 to 2 minutes. Remove the string and carve the roast into thin slice. Serve with the apricot sauce.