Find the crate that holds the Goxan Ceremonial Mortar.
The Three Spears Ogran would have some kind of bowl for breaking down the Gox Berries. It would have to be resistant enough to withstand the corrosive juices that the Gox Berries will render.
Pieces of the crate lay scattered on the ground.
The contents of this crate have been looted, and from the smiley faces drawn in the scattered mess left behind, you are certain it was nidgits.