The filling for these unusual buns is at once sweet and savory, a combination of plump cubes of marinated chicken and bits of dusky Chinese black mushrooms, bound in a light sauce. It is delicious on its own as a hot stir-fry and very special as a filling for buns.
In a food processor fitted with the steel knife or in a blender, blend the egg whites, wine, salt, and cornstarch until thoroughly smooth and thick, 30–60 seconds. Toss well with the chicken, stirring with your fingers, seal airtight, and refrigerate 8–24 hours to allow the chicken to absorb the marinade. The longer it marinates, the more tender and juicy it will be. Bring to room temperature before cooking.
While the chicken is marinating, soak the mushrooms in cold or hot water to cover until soft and spongy, 20 minutes to an hour. Drain, snip off the stems with scissors, then rinse the caps to dislodge any sand trapped in the gills. Squeeze gently to remove excess water, then mince the caps. Minced, they may be sealed airtight and refrigerated overnight. If you are using fresh mushrooms, brush clean and chop just prior to cooking.
If you are using bamboo shoots, blanch them in plain simmering water to cover for 15 seconds, then drain and flush with cold water until chilled. Seal airtight, and refrigerate until use.
Combine the soy, sugar, pepper, and sesame oil. In a second bowl, stir the cornstarch mixture until smooth and leave the spoon in the bowl. Have all the ingredients for the filling within easy reach of your stovetop.
Stir the chicken to loosen the pieces, then velvet it in oil or water. Diced chicken will turn 90 percent white in as little as 10 seconds, so be prepared to remove it swiftly, sooner rather than later if in doubt. If the chicken is only 70 percent white, it will still be better than if you have cooked it too long. As soon as the chicken is velveted, proceed to stir-fry the filling.
Heat a wok or heavy skillet over high heat until hot enough to evaporate a bead of water on contact. Add 1½ tablespoons oil, swirl to coat the pan, then reduce the heat to medium-high. When the oil is hot enough to sizzle one bit of scallion on contact, add the scallion and stir several seconds until foamy and fragrant, adjusting the heat so it sizzles without scorching. Add the mushrooms and the bamboo shoots if you are using them and stir to gloss and combine, about 15 seconds. Adjust the heat to maintain a merry sizzle and dribble in a bit more oil from the side of the pan if needed to prevent sticking. When the mixture is fragrant, add the chicken and toss briskly several times to mix. Add the seasonings, stir two or three times to blend, then give the cornstarch mixture a quick stir to recombine it and add it to the pan. Stir just until the mixture becomes glossy and slightly thick, about 5–10 seconds, then turn off the heat. Remove the mixture to a shallow bowl if you are working well in advance, or spread it on a plate if you want to cool it quickly in the refrigerator or the freezer. It must be thoroughly cool when you start to shape the buns.
Cooled, the filling may be sealed airtight and refrigerated overnight. If you are not working in advance, make the filling while the dough is first rising, and chill it quickly as above.
Follow the instructions for proofing the yeast and making the dough, letting it rise and punching it down, and incorporating the baking powder.
Have ready twenty 2-inch square paper bases for the buns. If you do not have silicon (no-stick) parchment, use greased parchment or greased wax paper. Arrange the squares greased side up on two baking sheets. Put the sheets, the cool filling, two dry, lint-free towels, and a ruler alongside your work surface. Stir the filling to redistribute the seasonings.
With a sharp knife, divide the dough into two equal parts. Return one piece, cut side down, to the floured comer, and cover. Dust the board lightly with flour, and with your palms roll the other piece of dough into a smooth, even cylinder 10 inches long. Eying the ruler, cut the cylinder into 10 inch-thick slices, then set the slices cut side down on a floured surface and cover with a dry towel. Repeat with the remaining piece of dough. If your kitchen is warm or you are new to bun making and work slowly, transfer half the slices to a floured baking sheet, cover, and refrigerate to stall the yeast.
Remove the first slice from under the towel, dust both cut sides with flour, then flatten it with joined fingers. Rolling the dowel with one hand, roll from the outer edge almost into the center of the dough. Turn the dough a notch with your free hand, then roll again almost into the center of the dough. Repeat until you have a round dough wrapper 4½ inches in diameter, with evenly thin edges and a puffy, nickel-size belly in the center of the dough. If you roll with your right hand, your left hand should turn the dough a notch counterclockwise after each roll, as illustrated. If you roll with your left hand, your right hand should turn the dough clockwise after each roll.
Place about 2 tablespoons filling in the center of the dough round, mounding it so it stays humped in the center. If you are right-handed, grasp the edge of the dough round farthest away from you between the end of your right thumb and first finger, thumb on the inside positioned ½ inch below the edge of the dough. The job of your thumb will be to stay in place as an anchor during the pleating. The job of your first finger will be to move away from your thumb to catch the pleat, then move back toward the thumb to press the pleat into place. As the pleats build out from the thumb, it and the first finger will be separated by an increasingly thick accordion of dough. With your right hand in position, it is the job of the left hand to bring the dough to the right hand to be pleated. (If you are left-handed, read all this in reverse, as well as what follows.)
To begin pleating, grasp the edge of the dough round ½ inch to the left of your stationary thumb between your left thumb and first finger, here again with the thumb on the inside grasping the dough ½ inch down from the edge (so the resulting pleats are neither too shallow nor too deep). Bring the half-inch of dough over to the right thumb and index finger in an even fold, then straighten out your right finger briefly in order for it to catch the pleat before tacking it down against the stationary thumb. If the dough is properly firm, not too dry and not too moist, it will pleat securely.
When the pleat is secured, move your left thumb and first finger another half inch farther along the edge of the dough and bring the next bit of dough over to form the next pleat, with your right finger catching and tacking it down as before. Repeat the process, with the pleats building out from your thumb in a straight line, like a pushed-together accordion. As you pleat, the bun will turn clockwise on its own and the top will pleat shut around your stationary thumb.
With the trapped thumb doing the lifting, put the bun on your free palm. Extract the thumb, pinch together the open top of the bun, and twist it firmly closed in a topknot in a counterclockwise direction, as illustrated. (Remember, if you are a lefty, you will be proceeding in reverse.) At this point, the bun is shaped, a job that takes only 1 minute when you are proficient, in spite of the long-winded explanation!
Put the finished bun on the paper square, and cover with a dry towel. Continue to roll, fill, pleat, and twist the buns shut, one by one, in the same manner. As each is done, put it on a paper square on the baking sheet, keeping the buns covered and spaced 2 inches apart from one another.
(For details on steaming and how to improvise a steamer.)
Let the buns rise under the towel until the dough is springy to the touch, 30–60 minutes, depending on the temperature of the room. During the final minutes of rising, bring the water in your steaming vessel to a gushing boil over high heat.
Transfer the risen buns still on their paper squares to a steaming rack, spaced 1–1½ inches apart. (If you are forced to work in batches, place the remaining buns, now covered loosely but airtight in plastic, in the refrigerator or even the freezer to halt their rising.) Station the rack in place, reduce the heat to medium-high to maintain a strong, steady steam, then cover the steamer and steam the buns for 15 minutes. Turn off the heat and let the steam subside for 5 minutes, then remove the lid slowly, so the buns do not collapse with the sudden gush of cold air.
Serve the buns immediately, or hold them in the steamer set over low heat for up to 1 hour. Just before serving, mix a small dish of dip sauce for each person present, combining the soy, vinegar, sesame oil or chili oil to taste, and garnish with a sprinkling of scallion. Discard the paper, and serve the buns in the bamboo steamer or on a heated platter of contrasting color.
Leftover steamed buns may be left to cool, then sealed airtight and refrigerated several days. To rewarm, steam on paper squares over medium-high heat until hot, about 15 minutes.
Once the buns have risen, you may bake them instead of steaming them. Follow directions for applying an egg wash and baking.
Leftover baked buns may be sealed airtight in foil and reheated in a hot oven. They are OK, but not as good as rejuvenated steamed buns, the second time around.
© 1982 Barbara Tropp estate. All rights reserved.