Make the aburaage into pockets by making a slit in each sheet, and set aside. Mince the onion and set aside.
Mix all the ingredients together (including the sachet of sauce that comes with the natto) except for the aburaage.
Stuff the aburaage pouches with the Step 2 mixture, and secure the openings with toothpicks.
Fry both sides over a low heat until golden brown.
You can also cut easy-melt sliced cheese in two, then fold each slice in half and use in place of the pizza cheese.
During Step 2, taste the mixture and add more mayonnaise or other seasonings if needed.
Some users added soy sauce, shiso leaves, etc.
The mixture is also delicious if you add kimchi and use it as an omelet filling, as in Recipe ID: 1880952.
Story Behind this Recipe
Actually, when I made this for the first time I also made some pizza-flavored ones with wiener sausages instead of natto. But they didn't taste very good.
Fry the aburaage slowly over a low-medium heat so that the filling cooks through. If you're not a big fan of raw onions or in a hurry, microwave it for a bit before adding it to the Step 2 mixture. I also made this without tuna.