Cut the eggplants in half, slice thinly and soak in water.
Roughly chop up the onion.
Stir fry the onion in oil. When it's translucent add the eggplant slices and continue stir frying.
When the eggplant has softened and wilted, add the ● ingredients and stir fry until there's no more moisture left in the pan.
Add the ground sesame seeds at the end. Adjust the seasoning with umami seasoning, and leave to cool.
Make the dough: Put the cake flour, bread flour and salt in a bowl and mix well with chopsticks.
When the flours are mixed, pour in the boiling water and mix well with chopsticks.
Knead the dough until it's about the stiffness and consistency of your earlobes. Form the dough into a ball, cover with plastic wrap and leave to rest for an hour.
Roll portions of the dough into balls, flatten, put on some filling and wrap while stretching the edges of the dough. Form into flat round cakes.
Heat up a frying pan with oil, put in the oyaki and brown them on both sides.
When they have browned, add water halfway up the oyaki. Cover with a lid and steam-cook until there's no moisture left in the pan.
When there's almost no moisture left, the oyaki are done.
Wrap the oyaki in a moistened kitchen towel or plastic wrap to store.
Story Behind this Recipe
The oyaki I had at a restaurant were not that good. I wanted to make oyaki that I would be happy with, and made my own. Oyaki are regional speciality of Shinshu (current day Nagano prefecture), where they are often eaten as snacks.
It's best to flavor the oyaki filling well - it goes better with the dough. Try Shishu oyaki with fillings other than eggplant.