Why It Works
- Purging clams in changes of salt water guarantees that no sand or grit ends up in the soup bowl.
- Removing clams from the broth as they open prevents them from overcooking.
The briny juice of asari (Manila clams) is the star of this sophisticated miso soup, which is based on one served at Manhattan's EN Japanese Brasserie. Unlike many other kinds of dashi, the version here relies on clams instead of the more commonly used shaved bonito flakes.
- 1 pound (450g) small asari (Manila clams), cockles, or littleneck clams (about 2 dozen Manila clams or cockles, or 8 littlenecks)
- Cold water
- Kosher salt
- 2/3 ounce dried kombu (20g; about one 6- by 6-inch piece), rinsed in cold water
- 3 tablespoons (50g) mild miso, such as shiro (white) miso (see note)
- 1 tablespoon (15g) dark miso, such as aka (red) miso (see note)
- Mitsuba or watercress leaves, for garnish
Rinse clams under cold running water. Fill a large bowl with cold water, season with salt until water is salty like the sea (about 3% salt by weight), and add clams. Let stand for 30 minutes. Lift clams from purging water and discard water. Rinse out bowl. Repeat as many times as necessary until no sand or grit collects in bottom of bowl (usually between 1 and 3 times).
In a medium saucepan, combine kombu and clams with 3 1/2 cups (830ml) cold water and bring to a bare simmer over medium heat, about 8 minutes. Remove kombu as soon as bare simmer begins and discard or reserve for another use. (Kombu can be thinly sliced and tossed into a salad.)
Continue simmering, using tongs to transfer clams as they open to a large heatproof bowl, until all clams have opened. Skim any foam from the surface of the dashi. Return dashi to a clean medium saucepan and keep warm over low heat.
In a small bowl, whisk both misos with just enough dashi to form a thin paste. Off heat, whisk miso paste into dashi in saucepan.
Divide clams among warm bowls and spoon miso soup over them. Garnish with mitsuba or watercress leaves and serve right away.
This recipe calls for two different types of miso for a more complex flavor, but if you want to use just one, omit the 1 tablespoon dark miso and replace it with 1 additional tablespoon of the mild miso.