In a large pot, bring the water to a boil over high heat.
Add the ginger, hoisin sauce, chili paste, and half of the minced scallions.
Reduce the heat to low and let the broth simmer for 15 minutes to allow the flavors to meld.
Stir in the seitan strips, fresh rice noodles, tamari, and lime juice.
Continue to simmer gently.
To avoid destroying the miso's delicate flavor, temper it first.
Remove about ½ cup of the hot broth to a small bowl.
Whisk in the miso paste until it's completely smooth, then pour the mixture back into the main pot.
Stir in the toasted sesame oil and fresh bean sprouts.
Simmer for another 3 minutes, just until the sprouts are slightly tender but still have a crunch.
To serve, ladle the soup into four large bowls.
Garnish generously with the remaining fresh scallions and chopped cilantro.
Serve immediately.
Set up a toppings bar with extra lime wedges, fresh Thai basil leaves, sliced jalapeños, and sriracha so everyone can customize their bowl.
