Peel the potatoes. Cut into 6-8 equal-sized pieces. Place in a heat-resistant bowl, cover with cling film and heat in a microwave for approximately 6 minutes.
Cut the onions in half lengthways and then cut into 1 cm wide slices cutting from root to top. Cut the meat into bite-size pieces.
Heat a little cooking oil in a frying pan, then add the potatoes and ® onions and fry. When all the ingredients are coated in oil and starting to soften, add the mixture from (1).
Add the beef and stir quickly with cooking chopsticks. Turn up the heat and bring to the boil. Once the dish has boiled, lower the heat and put on a pre-moistened drop lid which sits directly on top of the ingredients. Simmer for about 7 minutes.
When the stock is about a third of its original volume, remove the drop lid and add the bonito flakes. Simmer for one more minute, reducing the stock still further, then garnish with kinome and serve.