- 3 ounces dried rice vermicelli (rice sticks; see Notes)
- 8 cups reduced-sodium chicken broth
- 2 tablespoons minced fresh ginger
- 1 scallion, trimmed
- 1 garlic clove, bruised with the side of a knife
- 3 ounces shiitakes, stems discarded, caps wiped clean and cut into 1/8-inch slices
- 4 ounces baby bok choy (about 4), outside leaves and stems trimmed, cut across into ½-inch strips (2 to 3 cups)
- 4 ounces frozen small cooked shrimp, shelled, thawed and blotted dry (about 1½ cups)
- 1 tablespoon soy sauce or tamari
- 1 tablespoon toasted sesame oil
- 1 tablespoon unseasoned Japanese rice vinegar
- ½ teaspoon chile oil, or to taste, or a pinch of red pepper flakes
- Kosher salt
- 1 cup fresh bean sprouts, rinsed and crisped in ice water
- ½ cup thin diagonal slices scallion greens
- Mint leaves
- Cilantro leaves
- Thai basil leaves
- Place the rice vermicelli in a large bowl and cover with room-temperature tap water. Let stand for about 1 hour, checking for tenderness occasionally. When the noodles are soft but still slightly firm to the bite, drain. (They should yield about 3 cups.)
- Meanwhile, for the broth: Combine the broth, ginger, scallion, and garlic in a large saucepan; heat to a boil. Cover and cook over low heat for 15 minutes. Set a strainer over a large bowl and strain the broth. Discard the solids.
- Pour the seasoned broth back into the saucepan. Add the shiitakes; cover and simmer for 10 minutes.
- Stir the bok choy, shrimp, and drained noodles into the simmering broth. Cover and cook for 5 minutes. Add the soy sauce, sesame oil, rice vinegar, and chile oil. Season to taste with salt.
- Ladle the soup into deep soup bowls, distributing the ingredients evenly. Sprinkle with the garnishes.