Japanese soup can be divided into two categories; miso soup and osuimono. Miso soup is soup, in which miso paste is dissolved in the katsuo dashi or niboshi dashi. Osuimono is clear soup with dashi without miso, and flavored lightly with soy sauce and/or salt. The dashi soup can be made from katsuobushi or kombu or the combination of both.
Tororo soup is one of osuimono, because it doesn’t use miso. But you don’t really need to make dashi for this soup, because tororo kombu, which is thinly shaved kombu itself is one of the ingredients. In a sense, it’s instant kombu dashi soup.
The soup made from shaved kombu cannot taste bad. It may look like white hair ball, but if you taste a bit of tororo kombu right out from the package, you can tell that it’s packed with umami flavor. Other than preparing osuimono, tororo kombu can be used to wrap onigiri, or add it on top of hot soba noodles or udon noodles to boost the flavor instantly.
Tororo kombu can be found at Japanese grocery stores, but I’ve never seen it at other Asian grocery stores.