Peel and rinse the potatoes, then finely grate them into a puree. You may add a little water while grating if needed. Transfer the mixture into a squeezing bag or cloth and squeeze out as much liquid as possible.

Pour the extracted potato liquid into a bowl and let it sit undisturbed for 10 minutes. Carefully pour off the clear water on top—what remains at the bottom is pure potato starch. Set aside.

Place the squeezed potato pulp into a large bowl. Add the reserved potato starch gradually, mixing with chopsticks first, then kneading by hand.

Knead for 5–8 minutes until the dough is smooth, cohesive, non-sticky, and not crumbly. If too soft, add more starch; if too dry, lightly wet your hands. Cover and let rest for 15 minutes.

Finely chop the pickled cabbage. Heat pork lard over low heat, add scallion whites and ginger, and sauté until fragrant.

Add the cabbage and stir-fry over medium heat for 3–5 minutes until aromatic and moisture evaporates. Season with salt, MSG, Sichuan pepper, and oyster sauce if using. Turn off the heat, stir in scallion greens, and let cool completely.

Divide the rested potato dough into 6–8 equal portions (about 80–100g each). Flatten each piece into a round wrapper with slightly thinner edges and a thicker center.

Add 25–30g cooled filling to the center. Gently gather the edges upward, press out trapped air, and pinch firmly to seal. Shape into a round or oval bun.

Place the buns onto a steamer lined with damp cloth or corn leaves, leaving space between each.

Bring water to a full boil. Steam the buns over medium heat for 15 minutes until the wrappers turn slightly translucent and elastic.

Turn off the heat and let them rest in the steamer for 2 minutes before opening the lid. Serve hot.