Remove heads and guts of the dried sardines. Snap in half. Add water and sardines into a pot, and soak for about 1 hour.
Turn on the heat. When it starts to boil, turn down the heat to low, and boil for 10 minutes.
Turn up the heat to medium, then add the daikon radish and aburaage. When the daikon radish softens, add the tofu.
Bring to a boil again, and add the miso and Japanese leek.
Story Behind this Recipe
It's ok to use dashi stock powder, but it's not quite as tasty as dashi, which took a long time to make. It's a waste to throw away the dried sardines after making dashi, so I left them in the soup. You can enjoy their taste by chewing them well.
The dashi tastes better if you soak the dried sardines in water for a long time. If you soak them the day before, it comes handy when you make breakfast.