Just think of it as Japanese stock. And it’s not just for miso soup either. Dashi is excellent with carrots. Or, to make it a light meal, serve it over a fried egg topped with bean sprouts, scallions, and fried shallots.
You can use either dried shitake mushrooms or whatever combination of fresh you have lying around (I had a bunch of stems left over from a previous dish).
Kombu, dried kelp, sometimes called konbu or dashima, is rich in calcium. Do not wash kombu before using it; wipe with a damp cloth if you must.
1 piece kombu, about 4 × 7 inches
1 1/2 cups bonito (dried fish) flakes
1/8 cup dried shitake mushrooms or 1/4 cup fresh mushrooms, rinsed
2 tablespoon soy sauce
1/2 teaspoon mirin (sweet cooking rice wine)
Boil kombu in 6 cups water. Once rapidly boiling remove kombu and keep for other use (such as kombu relish). Turn off heat. Toss in mushrooms and bonito flakes. Cover and let sit for 30 minutes. Strain through cheesecloth. Add 1/2 teaspoon mirin and 2 tablespoons soy sauce, or to taste.