It is a base of Miso Soup.
Dashi (Japanese soup stock)
Kombu(dried kelp)…10g (1% of the amount of water)
Katsuobushi(dried bonito flakes)…20g (2% of the amount of water)
1. Pour water into a saucepan.
2. Soak the kombu in the water and place the saucepan over medium flame until it almost begins to boil. (about 10mins)
3. Once it boils, turn off the heat and add the katsuobushi. Wait for the Katsuobushi to settle to the bottom.(2-3mins)
4. Then, pour the dashi to another saucepan or bowl with a filter through a kitchen paper.
You can pour it into a container and keep the Dashi in the refrigerator for 2-3 days.
I often use Dashi pack. It could be purchased from Japanese grocery stores.