Soak the kazunoko in plenty of water to remove the excess salt. Change the water 3 times over the course of 1/2 a day. After removing the excess salt, remove the white membranes.
Bring the A ingredients to a boil.
Add a generous handful of bonito flakes, then turn off the heat after 2 minutes and cool.
After it cools, remove the bonito flakes.
Blot the kazunoko dry, then marinate them in the sauce. They taste best after 1/2 a day of marinating.
Story Behind this Recipe
I always make a ton of my favorite kazunoko every year.
Taste the kazunoko after soaking them in water to test the saltiness. Since they are marinated with kombu, the longer they marinate, the tastier they get. These have a subtle flavor, so leftovers will go well in a salad or in a Japanese side dish.