In a large pot, place the lamb and add the water. Bring to a boil. Remove any froth as it rises. Add the onion, salt, pepper, and turmeric. Reduce heat to medium, cover, and cook for 2 hours or until the meat separates from the bone. Remove the lamb from the pot, discard the bones, but save the broth for later use. Grind the meat in a food processor to form a paste (be s