Photo: Gary Soup (CC BY 2.0) via Wikimedia Commons · source
Called the Chinese hamburger: pork belly braised for hours in a spiced master stock, chopped with a little of its jellied juice and stuffed into a crisp, flaky baiji flatbread.
For the braise: 3 tbsp light soy sauce, 1 tbsp dark soy sauce, 2 tbsp Shaoxing wine, 30 g rock sugar, 3 slices ginger, 3 scallions, 2 star anise, 1 cinnamon stick, 2 bay leaves, 1 tsp Sichuan peppercorns, 1 black cardamom (optional), 2 dried chilies, 1 liter (4 cups) water
For the baiji: 300 g (2 1/2 cups) all-purpose flour, 3 g (1 tsp) instant yeast, 1/4 tsp baking powder, 170 ml (3/4 cup) warm water
1 green chili, chopped, and a handful of cilantro (optional)
How to make it
Blanch (10 min): Cover the pork with cold water, bring to a boil for 5 minutes, drain and rinse.
Braise (2 1/2 hr): Put the pork in a pot with all the braise ingredients and bring to a boil, then simmer, covered, until a chopstick goes through the skin easily, about 2 1/2 hours. Turn the pieces once.
Make the bread (30 min, plus rising): Mix the flour, yeast, baking powder and water into a firm dough, knead 5 minutes and rest 30 minutes. Divide into 6, roll each into a long strip, roll it up like a snail, stand it on end and flatten to a 10 cm (4 in) disc, 1.5 cm thick. Rest 15 minutes.
Cook the bread (15 min): Cook the discs in a dry heavy skillet over medium-low heat, 5 to 6 minutes a side, until golden with a white ring around the side, then crisp them 5 minutes in a 200 C (400 F) oven.
Chop and fill: Lift out the pork, chop it finely on a board with a cleaver along with the chili and cilantro, and spoon over 2 to 3 tbsp of the braising liquid. Split each bread open like a pocket (not all the way through) and stuff generously.
Tips
Keep the strained braising liquid; it's your master stock for the next batch.
A mix of lean and fat in each bun is the Xi'an way.