Pan Fry Version

1. Add sauce packet to natto and whisk until frothy.
2. Crack the eggs into a bowl and stir using chopsticks, breaking up the egg whites. Add the mayo, mentsuyu and sugar, and whisk throughly (without creating too many bubbles).
3. Whisk in the natto.
4. Heat the pan over medium heat and lightly oil it using a paper towel soaked in a small amount of oil. Ensure the entire surface of the pan is coated.
5. Add 1/3 of the mixture and tilt the pan to spread the mixture evenly across the surface. Let the egg cook until it is mostly set but still slightly runny on top. This makes it easier to roll.
6. Starting from one end, use chopsticks or a spatula to gently roll the egg towards the other end of the pan.
7. Once the first roll is complete, move it to the end of the pan where you started the roll. Lightly re-oil the pan and pour another thin layer (1/3 of mixture) of the egg mixture into the pan. Lift the rolled egg slightly to let the new mixture flow underneath it. Let the new layer cook until mostly set, then roll the existing roll back over the new layer, incorporating it into the roll.
8. Continue adding layers and rolling until all the egg mixture is used up. Each layer will build up the thickness of the tamagoyaki.
9. Transfer the tamagoyaki to a cutting board. If you have a bamboo sushi mat, you can use it to shape the roll into a more uniform shape by wrapping it and gently pressing. Slice the tamagoyaki into even pieces about 1 inch thick.

Microwave Version

1. Add sauce packet to natto and whisk until frothy.
2. Crack the eggs into a microwave safe bowl** and stir using chopsticks, breaking up the egg whites. Add the mayo, milk, mentsuyu and sugar, and whisk throughly (without creating too many bubbles).
3. Whisk in the natto.
4. Cover with a microwave safe lid or loosely with cling wrap. Microwave at 600 W for 1 minute. Stir and microwave for another minute. Stir and microwave for another 30-45 seconds or until the edges are set and the middle is slightly under (the residual heat will continue to cook it).
5. If using it in a sandwich, you can just flip it over onto your prepared bread. If making rolled omelette, flip it onto cling wrap and mold it gently into a log, twisting the ends.
6. Let it rest for about 5 minutes. Slice into 1 inch thick pieces and enjoy!