DIRECTIONS
Combine all of the crust ingredients in a jar and mix well.
Season the tuna with salt.
Beat the egg white in a shallow bowl until frothy.
Pour about 1 cup of the crust mixture onto a plate.
Store the remaining mix in a glass jar out of direct light.
Dip each piece of tuna into the egg white.
Let the excess drip off and then coat the fish on all sides with the crust mixture, patting it to make sure it adheres.
Place the tuna on a rack over a baking sheet and refrigerate while you heat the oil.
Pour 3-inches of oil into a large deep saucepan and heat to 365-degrees.
Fry the tuna one piece at a time until the dried onions brown, 1 minute or so.
Drain the fish on a rack.
Cut each portion into slices 1/3-inch thick and serve with soy sauce and wasabi paste.