Steps

1. Slice 1/2 onion into 5mm thick slices and trim the core.
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2. Peel 5g ginger and mince.
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3. Lightly coat 250g beef (sliced, for stir-fry) with 1 tbsp potato starch. 【This is the trick!】 It makes the meat tender and locks in the umami.
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4. Fill a frying pan with water and bring to a boil.
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5. Add the potato starch-coated beef to the boiling water, separating the slices, and heat over medium heat until it reboils.
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6. Once it reboils, turn off the heat, drain in a colander, and drain thoroughly. 【This is the trick!】 This removes impurities and odor from the meat, and also excess fat. If impurities remain after draining, rinse briefly with lukewarm water.
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7. Heat vegetable oil, to taste, in a frying pan over medium heat.
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8. Add the minced ginger and stir-fry until fragrant.
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9. Once fragrant, add the sliced onion and stir-fry, loosening the slices, for about 2 minutes until softened.
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10. Add the blanched beef and mix quickly.
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11. Add 2 tbsp sugar, 2 tbsp mirin, 2 tbsp sake, and 250ml water, mix, and bring to a boil. 【This is the trick!】 Adding the sweet seasonings first makes the meat tender and helps the flavor penetrate.
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12. Once boiling, simmer for about 1 minute. Stir occasionally to prevent the surface from drying out.
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13. Add 0.5 tsp konbu dashi powder and 2.5 tbsp soy sauce, and mix well.
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14. Simmer over medium to low-medium heat for 5 minutes. Stir occasionally while simmering.
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15. Turn off the heat after 5 minutes.
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16. Serve in bowls and garnish with pickled red ginger, to taste, as desired.
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