These buns are cooked in bamboo steamers which are available
in Chinese and gourmet cookware stores. The steamers are available
in various sizes separately or in sets of two or three tiers. For
cooking, the covered steamer(s) is placed over boiling water in
a wok or large saucepan.
Combine hoisin sauce, oyster sauce,
soy sauce and sesame oil. Chop pork and scallions finely. Heat vegetable
oil in wok or fry pan over high heat. Stir fry ginger and garlic
in the oil 1 minute. Stir in hoisin mixture. Cook and stir 2 minutes.
Combine 1/2 cup of the water and the cornstarch. Blend into hoisin
mixture. Cook and stir until liquid boils. Reduce heat to medium
and simmer 2 minutes. Stir in pork and onions. Remove from heat.
Combine flour, baking powder and salt in
large bowl. Cut or rub in shortening until mixture resembles bread
crumbs. Combine remaining 3/4 cup of the water and the vinegar.
Mix water-vinegar into flour until dough sticks together. Shape
dough into ball. Knead on lightly floured surface 6 or 8 times.
Cover with plastic wrap and let stand 20 minutes.
Uncover and knead 4 or 5 times. Divide dough into 12 equal portions. Shape
each portion into a smooth ball. Roll each ball of dough on lightly
floured surface into a 5- to 6-inch diameter circle. Brush around
edges lightly with water. Spoon a heaping tablespoon of pork mixture
onto center of each circle. Carefully pinch edges together to seal
dough around filling. Bring the two ends of dough over the seam
and pinch together.
Cut wax paper into twelve (5-inch) squares.
Brush one side of paper lightly with oil. Place a bun, seam side
down, on each square. Place buns with paper in single layer on steamer
rack over boiling water. Cover and steam buns until done, about