Trim the green beans and cut them into small 0.5cm pieces. Heat the oil in a pan over medium heat, add the ground pork, and stir-fry until the meat changes color and excess fat renders out.

Add Sichuan pepper, mushroom seasoning, light soy sauce, dark soy sauce, oyster sauce, soybean paste, and sweet bean paste. Stir well until fragrant and glossy. Add the green beans and cook for 3–4 minutes until just tender. Finish with scallions and ginger. Remove from heat and let the filling cool completely.

In a large bowl, mix the flour and one-rise yeast evenly. Gradually add the water while stirring with chopsticks until shaggy crumbs form. Knead by hand for about 5 minutes until the dough is smooth and elastic.

No need to let the dough rise yet. Roll it into a log and divide into 12–15 equal portions (about 40–50g each). Roll each piece into a ball, then flatten and roll into a round wrapper about 8–10cm wide, keeping the center thicker and edges thinner.

Place about 30g of cooled filling in the center of each wrapper. Pleat and pinch tightly to seal. Arrange the buns in a greased steamer or on parchment, leaving space between each bun.

Let the buns rise at room temperature for 20–30 minutes, until noticeably puffy and springy when gently pressed.

Bring water to a full boil. Steam the buns over medium heat for 15 minutes. Turn off the heat and let them rest in the steamer for 3 minutes before opening the lid. Serve hot.