Dashi Stock (Konbudashi)

Step 1
Wipe away any dirt from the kombu with a paper towel, being careful not to rub off the white powdery deposits on the seaweed. Place the kombu and water in a saucepan, and allow it to soak for 30 minutes to become soft.

Step 2
Remove the kombu from the water, and cut several lengthwise slits into the leaf. Return the kombu to the water, and bring it to a boil. As soon as the water begins to boil, remove the kombu to prevent the stock from becoming bitter.

Step 3
Stir the bonito flakes into the kombu-flavored water, bring back to a boil, and take the pan off the heat. Allow the water to cool. When the bonito flakes have settled to the bottom, strain the dashi through a strainer lined with cheesecloth or a coffee filter.