Japanese Rolled Omelet Sandwich

In a medium bowl, whisk together the eggs, dashi stock, sugar, soy sauce, and salt until well combined. Do not over-whisk, as you want to avoid too many bubbles.

Heat a non-stick rectangular tamagoyaki pan or a small non-stick skillet over medium-low heat. Add 1/2 teaspoon of vegetable oil and spread it evenly.

Pour about one-quarter of the egg mixture into the pan, tilting to coat the bottom evenly. Cook for 1-2 minutes until the edges are set but the center is still slightly wet.

Carefully roll the cooked egg from one end of the pan to the other. Push the rolled egg to one side of the pan.

Add another 1/4 teaspoon of oil to the empty part of the pan. Pour another quarter of the egg mixture into the pan, lifting the cooked roll slightly to allow the new egg mixture to flow underneath.

Cook for 1-2 minutes until the new layer is mostly set, then roll the cooked egg over the new layer, continuing to form a thicker omelet. Repeat this process with the remaining egg mixture and oil until all the egg is used and you have a thick, rolled omelet.

Remove the tamagoyaki from the pan and let it cool slightly on a cutting board. Once cooled, slice the tamagoyaki into two equal portions.

Spread 1 tablespoon of Japanese mayonnaise on two slices of shokupan. Place one portion of tamagoyaki on each mayonnaise-coated slice.

Top with the remaining two slices of shokupan to form two sandwiches. Gently press down and slice each sandwich in half, if desired, before serving.