This quick and easy stock has many uses in Japanese cooking, including dipping sauces, noodle dishes, and, most commonly, as the base for Miso Soup. It calls for just two ingredients -- kombu and bonito flakes -- and water. This recipe appears in our cookbook Martha Stewart's Cooking School.
Kombu (also called kelp) is a type of sun-dried seaweed that has been processed into sheets. It should not be rinsed with water before using or it will lose some of its flavor; instead, lightly wipe it with a dry cloth. Unopened packages will keep indefinitely; after opening, store kombu in a resealable plastic bag in a cool, dry place and use within 6 months.
Bonito flakes are made by boiling, smoking, sun-Âdrying, and then flaking fresh bonito, a type of small tuna. Store in an airtight container in a cool, dry spot for as long as a year (check the label for a freshness date).