In a large pot, combine 4 cups of water, 2 lime leaves, a piece of kombu, and 1 tablespoon of minced ginger. Bring to a gentle simmer over medium heat for about 5 minutes until aromatic.

Slice mushrooms, prepare bok choy by cutting into quarters, and shred a carrot for garnish.

In a small bowl, whisk together 2 tablespoons of miso paste, 2 tablespoons of peanut butter, 2 tablespoons of soy sauce, and a splash of water until smooth.

Increase the heat to bring the broth to a rolling boil. Add 4 ounces of rice noodles and the sliced mushrooms. Cook for about 3 minutes until soft.

Add the chopped bok choy into the pot and simmer for an additional 2-3 minutes until the greens are tender.

Reduce the heat to low and stir in the miso and peanut butter mixture until creamy and well-combined.

Ladle the soup into bowls and garnish with shredded carrot and a lemon wedge before serving.