In a large pot, heat the vegetable oil over medium heat.
Add the minced garlic and sliced ginger, and sauté until fragrant.
Add the pork belly slices and brown them on both sides.
Stir in the soy sauce, dark soy sauce, rice wine, brown sugar, star anise, and water.
Bring to a boil, then reduce the heat to low and simmer for about 1.5 to 2 hours, or until the pork is tender and the sauce has thickened.
In a mixing bowl, combine the flour, sugar, salt, and instant yeast.
Add the warm water and vegetable oil, and mix until a dough forms.
Knead the dough on a floured surface for about 10 minutes, until it becomes smooth and elastic.
Place the dough in a lightly oiled bowl, cover with a damp cloth, and let it rise in a warm place for about 1 hour, or until it doubles in size.
Punch down the dough and divide it into 8 equal pieces. Roll each piece into a ball and then flatten it into an oval shape.
Fold each oval in half and place each bun on a small piece of parchment paper.
Let the buns rise for another 30 minutes.
Set up a steamer and bring the water to a boil.
Place the buns with the parchment paper in the steamer, making sure they are not touching each other.
Steam the buns for about 10-12 minutes, or until they are puffed up and cooked through.
In a bowl, combine the rice vinegar, sugar, and salt.
Add the sliced cucumbers and carrots, and toss to coat.
Let the vegetables sit for at least 15 minutes to pickle.
Open each steamed bun and spread a little hoisin sauce on the inside.
Add a slice of braised pork belly, some pickled vegetables, fresh cilantro leaves, and a sprinkle of crushed peanuts.
Drizzle with sriracha sauce if desired.
Enjoy your meal!