ball or triangle with your hands. if you don’t want to use your hands, sprinkle a little sumac in the center of a sheet of plastic wrap. scoop a little rice over the seasoning and gather the plastic up around it. twist and mold it into whatever shape you want.
dip the rice ball edges into more sumac mix and wrap with a half sheet of nori.
if you will not be eating the rice balls right away, wrap them in plastic wrap and keep the nori separate until ready to serve. you can also freeze the rice balls, just keep them in another plastic zipper bag to shield them against frost. 