This stock soup is for broiled eel ochazuke. Garnish with mitsuba and wasabi, pour on the dashi stock, and enjoy.
I've been making this dashi stock for a long time.See how to make eel sauce (Recipe ID: 623506) here, and the instructions for Broiled Eel Rice Bowl (A Nagoya Speciality) here (Recipe ID: 1896927).
You can also make this with dashi stock granules, but you'll get a more authentic flavor by using bonito flakes and kombu.
Enjoy Japanese food around the world.