Cut the pork into bite-sized pieces and sprinkle with the mirin. Coat with katakuriko. Slice the onion to about 5 mm thick.
Put a little bit of dashi stock in a frying pan, and stir fry the onion until it changes color.
Add the meat and stir fry until it just starts to change color.
Add the rest of the dashi stock and skim off the scum. Add the soy sauce, mirin and sake and simmer for 3 to 4 minutes.
Add the beaten egg, turn down the heat to low and put on a lid.
Once the egg is soft set, turn off the heat. Add some roughly chopped mitsuba and put the lid back on for a minute to steam.
Finished. Add an umeboshi plum to taste.
Story Behind this Recipe
My mother used to make this all the time. (She used to use oil at Step 2.) It's good if you just start simmering it in dashi stock, but the onion becomes sweeter and the meat doesn't get dried out and stay tender if you stir fry them in advance.
Add some shimeji mushrooms or whatever you like. The umeboshi plum is my addition. We put it in the bowl at the last minute before eating and mix it in. It adds a very refreshing flavor. Please add this to your taste.