Spiced tofu dumplings with mushroom broth

Ingredients

• 3 1/2 oz spiced tofu
• 8 dumpling wrappers
• 6 1/3 oz shimeji mushrooms
• 6 1/3 oz beech mushrooms
• 3 1/2 oz dried shitake mushrooms
• 8 3/4 oz black trumpet mushrooms
• 10 water chestnuts
• 3 cloves garlic
• 2 oz ginger (divided)
• 1 carrot
• 1 3/4 oz celery root
• 3 onions
• 1/4 cup fish sauce (divided)
• 3/4 cup dark rice vinegar
• 6 1/3 cups water
• 1 tsp salt
• 1/2 oz scallions (divided)
• 1 tsp sesame seeds
• 1 tsp starch
• bonito flakes for garnish