Baked Pork Buns (Char Siu Bao)
adapted from The Chinese Kitchen by Eileen Yin-Fei Lo

Dough:
One 1/4-ounce envelope active dry yeast
1/3 cup sugar
1/2 cup warm water (110 F)
2 cups bread flour
1 large egg, beaten
3 TB lard or oil
1/2 tsp salt
1 1/2 tbsp scallion-infused oil or plain oil (optional)

In a large mixing bowl, dissolve the yeast and sugar in the hot water. 
Put in a warm place for 30 minutes to 1 hour, depending on the outside 
temperature. (It will take longer in cooler weather.)  When the yeast rises and brownish foam appears on top, add the flour,  salt, oil and half the egg, stirring constantly with your hand.

When the mixture becomes cohesive, sprinkle the work 
surface with flour and place the dough on it. Continue kneading for 
about 15 minutes, picking up the dough with a scraper and flouring the 
work surface to prevent sticking. When smooth and elastic, place the 
dough in a large bowl. Cover with a damp cloth or plastic wrap and put 
in a warm place for 2 to 4 hours, depending on the temperature. The 
dough is ready when it has tripled in size.
 

Filling (make while the dough is rising):
5 TB low-sodium chicken stock skimmed of fat (Cynthia says: I used my roast 
pork drippings, skimmed)
1 TB oyster sauce
2 1/2 tsp sugar
2 1/4 tsp tapioca starch or cornstarch
1 1/2 tsp dark soy sauce
Pinch ground white pepper
1 TB oil
1 small onion, cut into 1/4-inch pieces
3/4 cup barbecued pork, cut into 1/2-inch pieces
1/4 cup bamboo shoots
1 1/2 tsp Shao Xing rice wine or gin
1 tsp toasted sesame oil

In a small bowl, combine chicken stock, oyster sauce, sugar, your choice of
starch, soy sauce, and white pepper; set aside.

Heat a wok over high heat for 40 seconds and add oil. Coat wok with 
oil using a spatula. When a wisp of white smoke appears, add onion. 
Lower heat to medium, and cook until onion turns light brown, about 2 
minutes. Raise heat to high, add pork, and cook, stirring, for 2 
minutes. Add wine, and stir to combine.

Stir the reserved stock mixture and add it to the wok. Cook, stirring, 
until the sauce thickens and turns brown, 1 to 1 1/2 minutes. Add 
sesame oil, and stir to combine. Transfer to a shallow dish. Cool to 
room temperature.
 
Buns:
Heat the oven to 350F. Cut parchment paper into 12 pieces, 3 1/2 
inches square. Or, grease a large piece of foil. Remove the dough from 
the bowl, knead several times, then roll out into a cylinder 12 inches 
long. Divide into 1-inch pieces.

Work with one piece at a time, keeping the others covered with a damp 
cloth. Roll each piece into a ball.

Press with your fingers to create a well in the ball. Place 1 1/2 tbsp 
of the filling into the well, hold a bun in one hand, and with the 
other turn the bun, pinching it closed. Press firmly to seal. Place 
the bun, seam side down, on the parchment paper or foil. Repeat until 
all 12 are done.

Place the buns on a cookie sheet, at least 2 inches apart to allow for 
expansion. Place the buns in a warm place to rise for 1 hour. Spritz 
each bun lightly with warm water. Make an egg wash by taking the 
remaining beaten egg and combining it with an equal amount of water. 
Brush each bun with the egg mixture.
 
Bake for 15 to 20 minutes, or until golden brown. Halfway through the 
baking time, turn the cookie sheet around.
 
As the buns cool, their crusts will become slightly hard. If you want 
them to remain soft, brush lightly with oil immediately after baking.