6 ounces boneless pork loin, cut into 2-inch by ⅛-inch slices
1 cup (7 ounces) ½-inch cubed soft tofu
½ cup julienned bamboo shoots
1 large egg, lightly beaten
Cilantro leaves, for garnish
Thinly sliced scallions, for garnish
Directions
Make the pork stock: Preheat the oven to 425°. Line a sheet tray with parchment paper and add the pork bones. Roast until golden brown, 1 hour. Transfer the bones to a large stockpot, along with the water, dried shiitake mushrooms, garlic, scallions, onion and ginger. Bring to a boil over high heat, reduce to a simmer and cook until it's reduced by half, about 2½ hours. Strain the stock, discarding the bones, and return the stock to the pot. Make ahead: Store the stock in the fridge for up to 3 days or freeze it for up to 3 months.
In a small bowl, add the dried lily buds and cover with ¾ cup boiling water. Let it sit until soft, 10 minutes, then drain and discard the soaking liquid. In a separate small bowl, add the dried wood ear mushrooms and cover with ¾ cup boiling water. Let sit until soft, 15 minutes, then drain and reserve the soaking liquid. Cut the mushrooms and lily buds into 2-inch pieces and set them aside. Whisk the cornstarch into the mushroom soaking liquid until smooth.
Return the pork stock to medium-high heat and bring it to a simmer. Add the Shaoxing wine, red wine vinegar, ground white pepper, red chile flakes and salt. Add the cornstarch slurry and pork. Cook until the pork is tender, about 3 minutes. Stir in the reserved mushrooms and lily buds, tofu and bamboo shoots. Reduce the heat to a bare simmer, and slowly pour the egg into the broth in a thin stream. Let it sit for 15 seconds, then stir to incorporate.
Divide the soup between bowls and garnish it with chile flakes, cilantro leaves and sliced scallions. Serve immediately.