Sardine "meatball" soup with pink Asian radish, mibuna and udon noodles.
We found this recipe for a noodle soup with mibuna, which is apparently a characteristic vegetable of Kyoto, Japan. The meatballs are made of chopped sardine (we used tinned, but fresh would probably have produced a better texture), flour, miso paste and ginger. The vegetables are simmered in a dashi broth, and then the "meatballs" are added and simmered until they are warmed through. The soup broth is finally flavored with a bit more miso.
Dashi is one of the basic ingredients in Japanese cuisine - it is a stock made of simmered seaweed and bonito fish flakes. We purchased an "instant" dried dashi powder to save a little labor, but one of these days we should probably invest in the real ingredients. For what it's worth, we had been making miso soup for years with just miso paste added to the water, and it REALLY is better with the dashi.