Place the pomegranate juice, sugar, and lemon juice in a 4-quart saucepan set over medium heat. Cook, stirring occasionally, until the sugar has completely dissolved. Once the sugar has dissolved, reduce the heat to medium-low and cook until the mixture has reduced to 1 cup, approximately 70 minutes. Remove from the heat and allow to cool in the saucepan for 30 minutes. Transfer to a glass jar and allow to cool completely.
Grilled Leg of Lamb with Pomegranate Molasses
Heat grill to 375ºF.
Unroll the lamb and brush on all sides with the molasses. Season on all sides with salt and pepper. Roll the lamb up and secure with butchers' twine.
Place the lamb over indirect heat and cook for 15 minutes, then brush with the molasses again. Rotate 1/4 turn and cook for another 15 minutes. Complete the brushing and turning procedure 2 more times until the lamb reaches an internal temperature of 130ºF, or a total cooking time of approximately 1 hour. Remove from the heat and allow to rest 10 minutes before slicing and serving. Serve with additional molasses, if desired.