Chop the mitsuba into 3 cm pieces. Beat the egg in a bowl.
Combine the water and dashi stock granules in a pot to heat. When it starts boiling, add the mirin, and season with salt and soy sauce.
Once the soup is boiling, swirl in the beaten egg slowly through chopsticks.
Immediately crank up the heat to high for 5 seconds, then turn the heat off. Add mitsuba and cover with a lid and steam for a minute.
Serve in a soup bowl and it's done!
Story Behind this Recipe
I often make this whenever I need to serve soup with a meal.
The tip for making fluffy egg is not to over-cook it. Crank up the heat to the highest setting for a few seconds, turn off immediately, then cover with a lid and wait for a minute. I only added an egg and mitsuba, but it's also good with shiitake or shimeji mushroom. If you don't have mitsuba, use finely chopped Japanese leek.