Q. Can Ashkenazim eat during Pessach corn bread, such as tortilas, that were prepared with all the care of processing Matza?
A. There are many Poiskim who permit eating kitnios that were baked with all the stringencies normally applied to the preparation of matza. They argue that the lesser prohibition, (kitnios), can not be more severe than the principal chometz biblical proscription (Maharsha"k in Korban Pesach 153,1 and Yosef Daas 8 – Chayei Adam, klal 127,1), and if the five types of grain can be prepared not to ferment, certainly so can be done with kitnios. Beer Itzchok (11) mentions that it was customary to bake matzos from kitnios that were inspected properly before Pesach.
However there are other Poiskim that consider the prohibition of kitnios to be an original decree and therefore they are forbidden in any presentation or way of preparation, even when eaten raw. (Maamar Mordechai 32 – Tzofnas Paaneach 2,42 – Mor Uketzio), so too is the opinion of Horav Shlomo Miller Shlit"a.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit"a