I read the Mirgon Dower's Head quest and realised the glowing skull needed for this quest is dropped by alot of the skellies in Kurn's Tower, so I gave one of these dropped glowing skulls to the cook and got this Skull of Torture in return.
You DO NOT need to fulfill the quest requirements of mixing and combining hard to find items. Just take this dropped item to the cook and get your reward, then kill him and get a nice shield too!