Onigirazu (Rice Sandwich)

Rinse the Japanese short-grain rice thoroughly under cold water until the water runs clear. Cook the Japanese short-grain rice in a rice cooker according to its instructions, or in a pot with 240g of water, bringing to a boil, then simmering covered for 15 minutes, and resting off heat for 10 minutes.

While the Japanese short-grain rice cooks, prepare the fillings. For the tuna mayo, drain the Canned tuna in water completely. In a small bowl, combine the drained Canned tuna in water with Japanese mayonnaise and 2g of Koikuchi soy sauce. Mix well.

For the tamagoyaki, crack the Eggs into a bowl and whisk lightly. Add Mirin, Dashi stock, Sugar, Salt, and the remaining 3g of Koikuchi soy sauce to the Eggs and mix until just combined, being careful not to create too many bubbles.