In a large mixing bowl, combine 4 cups of all-purpose flour, 2 teaspoons of instant dry yeast, 1 tablespoon of sugar, 1 teaspoon of salt, and 2 tablespoons of roasted sesame seeds. Gradually pour in 1 cup of warm soy milk and 2 tablespoons of toasted sesame oil, stirring until a dough starts to form. Knead the mixture on a floured surface for about 10 minutes, until smooth. Cover and let it rise in a warm spot for at least 2 hours, or until doubled in size.

While the dough is rising, bring a pot of water to boil, add 2 ounces of uncooked vermicelli noodles, and soak for 7-8 minutes until soft. Drain and chop the noodles roughly. In a pan over medium heat, add 1 tablespoon of neutral oil, then sauté 1 cup of chopped scallions, 1 cup of shredded carrots, and 2 cups of raw shredded cabbage for 4-5 minutes, until tender. Stir in the noodles, 2 tablespoons of soy sauce, and a pinch of salt, allowing the filling to cool completely.

Once the dough has risen, punch it down to release air bubbles and divide it into 12-16 equal pieces. Roll each piece into a ball and flatten slightly with your hands. Using a rolling pin, roll each ball into a thin circle, approximately 3-5 inches in diameter. Keep the wrappers covered with a damp cloth to prevent them from drying out while you work on assembling the buns.

Take one of the rolled-out wrappers and place 2-3 tablespoons of the vegetable filling in the center. Carefully fold the edges over the filling and pinch them together to seal tightly. Twist the top to ensure it's securely closed, creating a nice bun shape. Repeat this process until all the filling is used, ensuring the Pan-Fried Cabbage and Noodle Buns are well sealed to avoid any spillage during cooking.

Heat a non-stick pan over medium heat and add 2 tablespoons of neutral oil. Once hot, place the buns creased-side down in the pan, making sure to leave space between each bun. Fry the buns for about 4-5 minutes, or until the bottom turns golden brown and crisp. Carefully add 1/2 cup of water to the pan, cover with a lid, and let them steam for about 5-6 minutes until fully cooked. Remove the lid to let any remaining moisture evaporate before serving.