In a medium sized pot, bring the water to a vigorous boil on high heat. Lower heat to medium high.

Add in the apple cider vinegar, black vinegar, soy sauce, white pepper and salt, stirring until thoroughly dissolved.

Add the shiitake and woodear mushrooms, stirring gently. Allow to simmer for about 5 minutes, stirring occasionally.

Turn off the heat and drizzle in the sesame oil, stirring once again to mix.

Ladle into bowls and garnish with the sliced scallions. Serve immediately.