In a large mixing bowl, combine all-purpose flour, instant dry yeast, sugar, and salt. Create a well in the center and pour in warm soy milk and toasted sesame oil. Mix vigorously for about 5 minutes until the dough forms. Cover with a damp towel and let rise for 2 hours until doubled in size.

Soak vermicelli noodles in hot water for about 5 minutes until soft, then drain and chop finely. In a skillet, heat neutral oil over medium heat. Sauté raw shredded cabbage, shredded carrot, and chopped scallions for 4-5 minutes until tender. Stir in chopped noodles, soy sauce, and a pinch of salt, cooking for an additional 2-3 minutes before draining any excess liquid.

After the dough has risen, gently punch it down. Divide into 12 equal pieces and roll each piece into a ball. Flatten each ball into circles about 3-5 inches in diameter, making sure the wrappers are thin but sturdy.

Place a generous spoonful of the filling in the center of each wrapper. Pinch the edges together to seal, twisting the top lightly for a pleated design. Place each bun on a tray lined with parchment paper.

Heat neutral oil in a non-stick skillet over medium heat. Carefully place buns in the pan with the creased side down. Cook for 4-5 minutes until golden brown. Add about 1 tablespoon of water per bun, cover with a lid, and cook for another 5-6 minutes until the water evaporates.

Remove the buns from the skillet and serve hot. Pair with a dipping sauce of soy sauce, sugar, and chili flakes for extra flavor.