Preheat your oven to 325°F.
In a small mixing bowl, combine the Coriander, Oregano, Ancho Chili Powder, Cumin, Black Pepper, Cocoa Powder, Sugar, Allspice, Cinnamon, and Crushed Garlic. Mix well, then coat the lamb on the baking sheet.
Once the mole dry rub has been coated on the lamb, transfer the lamb to the roasting dish and set it on top of the onions and garlic.
Pour the chicken broth around it, then seal it tightly with aluminum foil, and place it in the oven.
After 2 hours, check to make sure there is still plenty of broth and baste the leg of lamb with the juices. (If more chicken broth is needed, add an extra cup.) Repeat at hour 3 and 4.
During the last 10 minutes, remove the aluminum foil and broil on low to form a nice crust.
Remove from the oven after 4.5-5 hours. Let the leg of lamb rest for 20 minutes, then lightly shred it into large chunks. (It should separate beautifully with the lightest prompting of a fork!)
Serve with the Green Apple Tomatillo Sauce, some chopped cilantro and enjoy!