Nigiri Sushi with Omelet (Tamagosushi)
Beat the whole eggs with the egg yolk. Stir in sugar, soy sauce and a pinch of salt until the sugar has dissolved. Beat the egg mixture until fluffy. Pour the egg mixture into a small rectangular dish brushed with oil. Wrap the dish with aluminum foil and cook the egg mixture in a covered steamer over almost boiling water for about 30 minutes. Remove omelet from the dish and allow to cool.
Meanwhile, divide the sushi rice into 12 portions and shape each portion into an oblong shape with hands (moistened in water and vinegar).
Cut the cooled egg omelet into 12 oblong slices. Lay a piece of egg custard in your hand and coat one side with a little wasabi. Place the egg piece on top of a rice oblong, pressing gently so that it retains its shape. In this manner produce 12 nigiri sushi.
Cut nori into 12 strips. Wrap each egg and rice nigiri in a strip of nori, moistening the ends slightly to stick to each other and seal. Serve the nigiri sushi (rice side down) with your choice of dipping sauce, if desired.