How to Make It
In a small bowl, cover the lily buds with boiling water and let stand until softened, about 10 minutes. In another small bowl, cover the dried wood ear mushrooms with boiling water and let stand until softened, about 20 to 30 minutes. Rinse and coarsely chop.
In a medium saucepan, cover the rice with 1 3/4 cups of the water and bring to a boil. Cover and simmer over very low heat for 12 minutes. Remove from the heat without lifting the lid and let stand, covered, for 5 minutes. Using a fork, fluff the rice; cover and set aside.
In a large pot, heat the oil over moderately high heat. Add the bok choy and cook, stirring, for 1 to 2 minutes, until just wilted. Add the garlic, scallions, ginger and pork, and cook, stirring to break up the meat, until no pink remains, about 3 to 5 minutes. Add the stock and bring to a simmer. Measure out 1/4 cup of the stock and set aside in a small bowl. Add the lily buds, mushrooms, tofu, bamboo shoots, vinegar, soy sauce, sesame oil, pepper and sugar and return to a simmer. Using a circular motion, drizzle in the eggs and stir the soup gently until the eggs are cooked, about 30 seconds. Stir the cornstarch into the reserved 1/4 cup of stock and then drizzle the mixture into the soup, stirring gently until slightly thickened, about 3 to 4 minutes.
Taste and add more of the vinegar and soy sauce if desired. Divide rice into bowls and ladle the soup over the rice. Serve with chili oil.
Lily buds, wood ear mushrooms, and Chinese black vinegar are available at Asian grocery stores.