If using dried shiitake or wood ear mushrooms, place them in warm water to rehydrate for 20–30 minutes. Squeeze out excess water and slice thinly. Reserve soaking liquid, strain and add up to 1/2 cup to the stock for extra flavor if desired.

In a large pot, combine the 6 cups stock and 1 cup water and bring to a gentle simmer over medium heat.

Add the julienned ginger, minced garlic and the white/light-green parts of the sliced green onions to the simmering stock. Let simmer 5 minutes to perfume the broth.

Add the sliced rehydrated (or fresh) shiitake and wood ear mushrooms to the pot and simmer another 3–4 minutes so they soften and release flavor.

Proteins & vegetables

If using pork: thinly slice 6 oz pork across the grain. Add the pork to the simmering broth and cook until just done, about 2–3 minutes depending on thickness.

Add the julienned bamboo shoots and the tofu matchsticks or cubes to the pot. Gently stir to distribute. Simmer 2–3 minutes so tofu warms through and bamboo shoots are heated.

Seasonings & thickener

Stir in 3 tbsp light soy sauce, 1 tsp dark soy sauce (if using), 1 tbsp Chinese black vinegar, 1 tsp rice vinegar (optional), 1 tsp white pepper, 1 tsp chili paste, and 1 tsp salt. Taste and adjust balance of salty/spicy/sour — add more vinegar for sourness, more chili for heat, or a dash more soy for saltiness.

Make the cornstarch slurry by whisking together 3 tsp cornstarch and 3 tbsp cold water until smooth. With the soup at a gentle simmer, slowly pour the slurry into the pot while stirring or in a thin stream; continue stirring until the broth slightly thickens, about 1 minute. The soup should be noticeably silky but still pourable.

Finishing & garnish

Slowly drizzle the lightly beaten egg into the simmering soup in a thin stream while stirring gently in one direction to create silky ribbons. Turn off the heat as soon as the egg is set into delicate strands.

Stir in 1 tsp sesame oil and additional 1/4 tsp white pepper (or to taste). Adjust seasoning one more time — add a splash more black vinegar or soy if needed.

Ladle soup into bowls and garnish with the reserved green parts of the scallions, chopped cilantro if using, and an extra grind of white pepper. Serve hot.