In a medium-large pot, heat the oil over medium.
Reduce the temperature to medium-low, then add the mushrooms. Let the mushrooms sit for about 5 minutes, then add the ginger, stir, and continue to cook until the mushrooms are tender, about 3 minutes—stirring occasionally.
Add the broth and bring to a low boil. Remove a half cup of broth and set aside. Add the noodles to the boiling broth, then simmer until the noodles are tender, about 4 minutes. Remove from heat.
Add the miso to the reserved broth, whisking to combine. Add the miso mixture to your noodles.
Add the spinach to your noodles, along with tamari or liquid aminos to taste.
Carefully spoon the broth and noodles into a large bowl, then top with fresh cilantro, thinly sliced green onion, shredded purple cabbage, grated carrot, toasted sesame oil, and sesame seeds.