2. Add sugar, soy sauce, mirin, and dashi stock (if using) to the eggs. Mix well.
3. Heat the tamagoyaki pan over medium heat and lightly oil it.
4. Pour a thin layer of the egg mixture into the pan. When it starts to set, roll it up with chopsticks.
5. Move the rolled egg to one side of the pan. Pour another thin layer of the egg mixture into the pan, lifting the rolled egg to let the new layer flow underneath. When it starts to set, roll it up with the first roll.
6. Repeat until all the egg mixture is used up. Remove from the pan and let it cool slightly before slicing.