Dried shiitake mushrooms provide depth of flavor and star anise lends its unique tangle of licorice, resin, and smokiness to this Asian-inspired split-pea soup. Ginger juice and watercress leaves offer bright finishes of taste and color to the soothing, familiar backdrop of split peas.
- ¾ ounce dried shiitake (about 10 small)
- 2 whole star anise “flowers”
- 2 cups boiling water, plus 4 cups additional water
- 1 tablespoon peanut oil
- 5 scallions, thinly sliced (keep white and green parts separate)
- 1 cup finely diced onion
- 2 teaspoons minced garlic
- ¼ cup dry sherry
- 1½ cups split peas, picked over and rinsed
- ½ teaspoon salt
- 5-inch chunk fresh ginger (about 4 ounces)
- 2 to 3 cups loosely packed watercress leaves (from 1 average bunch), coarsely chopped
- 1 to 3 tablespoons Japanese soy sauce (Shoyu or Tamari)
- 1½ to 3 teaspoons Asian (toasted) sesame oil (optional)
- 1 tablespoon toasted black sesame seeds, for garnish (optional)
1. Place the shiitake and star anise in a large glass measuring cup and pour the 2 cups boiling water over them. Cover and set aside until the mushrooms are tender enough to cut, usually about 10 minutes. Lift out mushrooms and star anise with a slotted spoon. Slice the caps thinly, discarding any stems (they are too woody to eat) as you go. Set the shiitake, star anise, and soaking liquid aside.
2. Heat the oil in a 6-quart or larger pressure cooker. Add the white part of the sliced scallions, the onion, and the garlic, and cook over medium-high heat, stirring frequently, until they soften slightly, about 2 minutes. Add the sherry and cook over high heat, stirring constantly, until the sherry evaporates, about 30 seconds. Add the 4 cups of water, split peas, sliced shiitake, star anise (discard any broken pieces), and salt. Pour in the shiitake soaking liquid, taking care to leave behind any grit on the bottom of the cup.
3. Cook at high pressure for 10 minutes. Allow the pressure to come down naturally.
4. While the soup is cooking, prepare the ginger juice: trim and grate the ginger. Once you have about a tablespoon, press to grate ginger, use a porcelain grater, available in Asian groceries, or the side of a box grater with rice-sized holes.
5. Once the pressure is down, remove the lid and stir in the ginger juice, scallion greens, watercress, soy sauce, and toasted sesame oi to taste. Garnish individual servings with black sesame seeds, if you wish.
The generous supply of meaty shiitake makes this soup substantial enough to serve as the main course. Opt for small shiitake-with dried caps no more than 1 inch across-if you can find them, as they rehydrate quickly. (About 10 of this size weigh ¾ ounce). If using larger ones, you may need to soak them longer; chop them into bite-sized morsels. You’ll find dried shiitake and star anise in Asian groceries and in some health-food stores.