- 4 cups Light Chicken Stock or canned low-sodium chicken broth
- 1 stalk of lemon grass; white part only, coarsely chopped and tied in a cheesecloth bundle
- ¼ teaspoon crushed red pepper
- 1 large shallot, thinly sliced
- 2 scallions (white parts only), cut on the diagonal into 1-inch pieces
- 1¼ pounds (12 to 18) littleneck clams
- 1 small (about 8 ounces) head of bok choy
- 4 ounces straw, honshimeji, or shiitake mushrooms
- 1½ ounces enoki
- ½ ripe tomato
- Kosher or sea salt
- 2 tablespoons fresh cilantro leaves
- Bring the stock, lemon grass, red pepper, shallot, and scallions to a boil in a large nonreactive pot. Reduce the heat and simmer, skimming any foam from the surface, for 30 minutes.
- Scrub the clams under cold running water. Rinse the bok choy, shake dry, and trim off the white ends. Slice crosswise into ¼-inch-wide ribbons. Leave straw mushrooms or honshimeji whole but stem, then slice shiitake caps, if using, ¼-inch thick. Trim the stem ends off the enoki and separate the clusters. Core the tomato, remove the seeds, and cut the pulp into ¼-inch strips.
- Remove the lemon grass bundle from the broth. Bring broth back to a boil. Add the clams and straw mushrooms, cover, and reduce the heat to medium. Steam the clams until they open, about 3 minutes. Stir often to give all the clams a chance to open. Any that do not open should be discarded.
- Stir in the bok choy, and cook over medium heat, stirring, for 1 minute. Stir in the enoki, and cook for 1 minute. Add the tomato strips. Season to taste with salt, top with the cilantro leaves, arid serve.
- Variation: To serve over jasmine rice, spoon about 1 cup cooked jasmine rice into each of 2 bowls. Transfer the soup solids with a slotted spoon, top each serving with cilantro leaves, and spoon the broth over all.