Bread from non-grain flour

Hi,

For bread made from a combination of non-grain flour and grain flour, such that the quantity of grain flour is less than an olive-sized amount in כדי אכילת פרס (the amount one normally eats in 8-10 minutes), one does recite HaMotzi beforehand, but the closing berachah is Borei Nefashot.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 1:70)

Have a great day,
Mordechai