To make egg white pancakes: Lightly beat egg whites with wheat starch, salt, and pepper until well combined. Heat a nonstick saute pan over medium-high heat. Add some oil and heat. Pour 2 teaspoons of the mixture into the pan, spreading it out into a shape of a circle, while making sure it is as thin as a piece of paper. Repeat with all of the batter.
In the bowl of a food processor, combine chicken, shrimp, mushrooms, fat, scallions, cilantro, water chestnut, white pepper, salt, sesame oil, and oyster sauce. Pulse until all the ingredients are chopped. Remove the leaves from several cilantro sprigs. Blanch sprigs in boiling water for 15 to 30 seconds to soften enough to be able to tie into a knot.
To make dim sum: Lay out an egg white pancake. Add some of the chicken meatball filling. Fold the pancake around the filling and tie the opening with the softened cilantro. Trim the top of the dumpling. Put the dumplings into a steamer, and cook for about 5 to 10 minutes.
Egg white sauce: heat the water and add the egg white, stirring vigorously, add 1 tablespoon flour and season with salt.
Garnish the dumplings with ground dried Virginia ham or crumbled hard-boiled egg yolk mixed with kosher salt and some egg white sauce.