On some uses of maize in the seirra of Ancash

"Maize, the most important food plant in the Sierra pof Ancash, is used uin a great variety of recipes. the most unusual use of maize and on wich apparently is not knwn outside Ancash is "tocos de maíz" or fermented maize […] For the preparation of "cancha" [and probably also pop corn] the indians of Ancash use a baked clay vessel called "tiesto" [olla canchera], wich is mound shaped and slightly ronded on the bottom. It has a small opening on the side and may or may not have a handle. They are genearlly 20-30 cm. in diameter"