Marinate The Pork Belly: In a large bowl or resealable bag, combine all marinade ingredients. Add the pork belly cubes and marinate for at least 4 hours, or preferably overnight, in the refrigerator. Remove pork belly from marinade, reserving the marinade.
Dry Rub The Pork Belly: In a small bowl, combine all dry rub ingredients. Rub the dry rub generously over the marinated pork belly cubes.
Grill the Pork Belly Burnt Ends: Preheat your BBQ to a low, indirect heat (around 250°F/120°C). If using a charcoal grill, create a two-zone fire. Place the dry-rubbed pork belly cubes directly on the grill grates, away from direct heat. Cook for 2-3 hours, or until the pork belly is very tender. Increase the heat on the BBQ to medium-high. In a saucepan, reduce the reserved marinade by half, simmering until it thickens slightly into a glaze. Brush the pork belly cubes generously with the reduced marinade glaze. Grill for 15-20 minutes, turning occasionally and brushing with the glaze, until the edges are crispy and caramelized (burnt ends).
Pickle The Vegetables and Grapes: In a saucepan, combine all pickling liquid ingredients. Bring to a simmer over medium heat until sugar dissolves. Place julienned carrots, daikon, and grapes in a heat proof container. Pour the hot pickling liquid over the vegetables and grapes. Let sit for at least 30 minutes, or preferably overnight, in the refrigerator.
Make the Gochujang Sauce: In a food processor or blender, combine all gochujang sauce ingredients. Blend until smooth.
Prepare Garlic-Ginger Oil: In a small saucepan, heat neutral oil over low heat. Add minced garlic and grated ginger. Gently heat until fragrant, but do not let them burn. Strain the oil to remove the solids.
Make The Bao Bun Dough: In a small bowl, combine warm milk, yeast, and 1 Tbsp sugar. Let stand for 5-10 minutes, or until foamy. In a large bowl, whisk together flour, salt, baking powder, and remaining sugar. Add the yeast mixture, shortening or lard, and garlic-ginger oil to the flour mixture. Mix until a shaggy dough forms. Turn the dough out onto a lightly floured surface and knead for 5-7 minutes, or until smooth and elastic. Gently knead in the finely chopped scallions until evenly distributed.
First Dough Proof: Place the dough in a lightly oiled bowl, turning to coat. Cover with plastic wrap or a clean kitchen towel and let rise in a warm place for 1-1.5 hours, or until doubled in size.
Portion and Second Proof: Punch down the dough and divide it into 21 equal portions (approximately 50 grams each). Shape each portion into a smooth ball. Place the balls on a lightly floured surface, cover with a clean kitchen towel or plastic wrap, and let them rest for 15-20 minutes. This second proof allows the gluten to relax, making them easier to shape.
Form Buns and Third Proof: Roll each portion into a small oval, then fold it in half like a taco shell. Place the shaped buns on individual squares of parchment paper. Arrange the buns in a steamer basket, leaving space between them. Cover the steamer basket with a clean kitchen towel or plastic wrap and let them proof for another 20-30 minutes, or until slightly puffed.
Steam: Place the buns on squares of parchment paper. Place the buns in a steamer basket, leaving space between them. Steam for 10-12 minutes, or until puffed and cooked through.
Assemble: Fill each steamed bao bun with pork belly burnt ends. Top with pickled vegetables and grapes. Drizzle with gochujang sauce. Garnish with fresh cilantro and chopped peanuts.
Serve immediately.