Warm the vegetable oil in a medium skillet over medium heat. Add the onin and a pinch of salt and cook, stirring occasionally, until tender, about 5 minutes. Add the cabbage and a pinch of salt and cook until tender, about 10 minutes. Add the garlic and ginger and cook, stirring occasionally, until tender and fragrant, about 3 minutes. Transfer to a medium bowl and cool completely.

In a medium skillet over medium heat, warm the vegetable oil. Add the onion and a pinch of salt and cook, stirring occasionally, until tender, about 5 minutes. Add the cabbage and a pinch of salt, and cook until tender, about 10 minutes. Add the garlic and ginger and cook, stirring occasionally, until tender and fragrant, about 3 minutes. Transfer to a medium bowl and cool completely.

Once cooled, add the chicken, bamboo shoots, sugar, bouillon powder, white pepper, 2 teaspoons of the tapioca starch, 1 teaspoon salt and the sesame oil to the bowl with the onion. Use your hands to stir the mixture together until well combined. Refrigerate the filling while you make the dough.

Line a baking sheet with parchment paper and set aside. Bring 2 cups water to a boil in a small pot.

Meanwhile, sift the wheat starch and remaining ⅔ cup tapioca starch through a fine-mesh strainer into a large bowl. Stir 1 teaspoon salt into the boiling water until dissolved, then slowly pour the water over the wheat starch mixture and mix with a wooden spoon or chopsticks. Cover and let rest for 5 minutes. Add the lard and knead until incorporated and the fat is absorbed into the dough and no longer greasy, 2 to 3 minutes.

Lightly dust a work surface with wheat starch and turn the dough out onto it. Divide into four equal portions and roll each portion into a 12-inch log. Cut each log into 8 even pieces. Roll each piece into a ball, then cover the dough balls with a damp paper towel or lint-free kitchen towel. Working with one piece of dough at a time, dust the dough with some wheat starch, press into a 3-inch round, then roll out with a rolling pin or dumpling dowel into a thin 4 ½- to 5-inch circle.

Lightly dust a work surface with wheat starch and turn the dough out onto it. Divide into four equal portions and roll each portion into a 12-inch log. Cut each log into 8 even pieces. Roll each piece into a ball, then cover the dough balls with a damp paper towel or lint-free kitchen towel. Working with one piece of dough at a time, dust the dough with some wheat starch, press into a 3-inch round, then roll out into a thin 4 ½- to 5-inch circle with a rolling pin or dumpling dowel.

Put a dough circle in front of you and place a level 1 ½ teaspoons of the chicken filling in the center. Use a small offset spatula to get under the dough and lift it off the work surface and into the palm of your hand; the dough will be tender so handle it gently. Use the fingers on your other hand to fold the dough over the filling, creating a half-moon with two open sides. Use your fingers to tuck the dough on the open sides inward, bringing the edges to meet. Lay the dumpling down onto the work surface and use your fingers to press the folded dough where the edges meet under the ghost head, then gently press the dough downward so that it flattens out to a long “sheet” no thicker than ⅛ inch. Use the offset spatula to lift the dumpling off the work surface and trim the bottom of the dough in a wavy design, like the bottom of a ghost’s sheet. You can make the ghost as long or as short as you like. Place the ghost dumpling on the prepared baking sheet and press 2 sesame seeds into the top part of each dumpling to create the ghost’s eyes. Cover with a damp paper towel or lint-free kitchen towel. Repeat with the remaining dough, filling and sesame seeds.

Fill a 12-inch skillet or wok with about 2 inches of water and place a 10-inch bamboo or metal steamer basket in the skillet. Make sure the water doesn’t touch the bottom of the insert. If it does, pour some out. Bring the water to a rolling boil, line the steamer basket with a perforated parchment circle and place 8 dumplings into the steamer basket, leaving about a ½ inch between each. Cover and steam until the filling is cooked through and the wrappers are translucent, 7 to 9 minutes. Cool for a minute to set the skin, then enjoy while warm. Continue steaming the remaining dumplings.