Soak the
tofu skin
in a large
bowl
of water until softened,
30 minutes
. Remove from the water. Line the sheets up on a
cutting board
and roll into a cylinder. Cut crosswise into 1-inch segments, at least a foot in length. In a medium
bowl
, combine the
ground pork
,
egg white
,
fresh ginger
,
kosher salt
,
ground white pepper
, 1/4 teaspoon of the
sugar
, the
light soy sauce
,
oyster sauce
, 2 teaspoons of the
cornstarch
, and the
dried shiitakes
. Mix with your hands to combine. Using about 2 tablespoons of the meat filling per segment of tofu skin, roll up the filling in the tofu skin, forming fairly tight cylinders. Combine the remaining teaspoon of soy sauce and the remaining teaspoon of cornstarch in a small
bowl
and stir with a fork until homogenous. Add the
chicken stock
and set aside. Heat the
vegetable oil
in a
wok
to 350°F. Fry the cylinders of tofu skin, a couple at a time, until the surface is light brown and somewhat puffed up. Remove with a slotted spoon and set aside. Line up all the fried rolls in a shallow bowl that can fit into a metal or bamboo
steamer
. Pour the sauce over the rolls, and steam over high heat for
15 minutes
, flipping the rolls halfway through. Steam until the skin has absorbed at least half of the sauce. Serve immediately, garnishing with
cilantro
if desired.