Heat 1/2 teaspoon avocado oil in a pot over medium heat. Add mushrooms and a pinch of salt. Cook until softened, about 3-4 minutes.

Move mushrooms aside. Add remaining 1/2 teaspoon avocado oil and sauté minced garlic until fragrant, about 30 seconds.

Add sliced baby bok choy and sauté for 1 minute until leaves just wilt.

Pour in 1 1/2 cups water and 1/2 teaspoon tamari, then add tofu cubes. Bring to a simmer.

Stir in 1 tablespoon white miso paste until dissolved. Taste and adjust tamari or miso if needed.

Ladle soup into a bowl and garnish with sliced scallion. Serve immediately.