Dough
Filling
In a hot skillet over medium high heat, sauté the Chinese sausages without oil for 2 minutes on each side. Then, transfer the sausages to another plate and set it aside.
To the same skillet, use a paper towel to wipe off the excess oil and add shallots, garlic, jicama, mushrooms, and salt. Sweat the vegetables for 3-4 minutes until translucent. Set this aside and let it cool completely.
In a large bowl, combine ground pork, sugar, chicken bouillon powder, ground pepper, oyster sauce, sesame oil, and cornstarch.
Once the vegetables are cooled, combine them with the ground pork mixture. Gently mix until well incorporated (but do not overmix.)
Scoop 1 ½ tablespoons of the meat mixture and flatten it into a pancake shape. Add the egg and 2-3 slices of Chinese sausage into the middle and fold the meat around it into the shape of a ball. This will yield around 12-14 meatballs. Cover and refrigerate.
Using the milk, 3 tablespoons of the flour, and ⅓ of the sugar, make a tangzhong by whisking over medium-high heat until it becomes thick like a paste. Cool the tangzhong by adding the water a bit at a time, then stir in the yeast. Let stand for 5-10 minutes
Attach a dough hook to the stand mixer. In the stand mixer bowl, combine all-purpose flour, sugar, salt, and tangzhong. Start with the lowest speed for 1 minute until the ingredients are combined. Increase the speed to 3 and let it knead for 10 minutes, adding oil halfway through. The dough should be smooth, elastic, soft, pliable, and slightly sticky (if the dough is too sticky, you may need to add more flour and knead some more.) Cover and let it rest for 15 minutes.
Lightly oil your hands and work surface. Then, knead the dough by hand for 1 minute, and form a ball. Divide it into 12 uniform pieces (about 75g each). Roll them into balls, cover them, and let them rest for an additional 15 minutes. (Pro tip: It's important to keep the dough covered when it is not in use to prevent it from drying out.)
Use a roller to flatten the dough, leaving it slightly thicker in the middle with flattened edges. Place a meatball in the middle and create small pleats to wrap it. Repeat until all the meat and dough is used up.
Cover and let the dough proof for 30 minutes.
In a steamer, add water and 1 tablespoon of vinegar. Bring to a boil. Arrange the buns in the steamer, leaving about an inch in between each. You may need to work in batches depending on the size of the steamer.
Steam for 20 minutes. Then, turn off the heat, leaving the lid on, and let it sit for 3 minutes. (Pro tip: Quickly exposing the banh bao to air will cause them to deflate.)
Serve warm. Enjoy!
