Flatten out a disk of the dough and add a ball of mung bean filling. The dough to filling ratio is up to you! I like about 1" in diameter, but you can make them bigger. Keep in mind they will slightly expand during cooking.
Try not to leave any air pockets inside, since the dough will already be expanding and adding air to the center. Close off the ball so there aren't any cracks.
Slightly roll in your hands to make a ball shape and then roll in a bowl of sesame seeds to coat thoroughly. Set aside for frying.