Heat a large skillet over medium heat and coat with a 2-count of sesame oil. Add the garlic and ginger to the pan and stir for 1 minute, until fragrant. Add the leek, bok choy, mushrooms, carrot, and cilantro. Season with salt and pepper. Stir and cook for 5 minutes, until the vegetables soften. Remove from the heat and let the vegetables cool to room temperature. Scrape the vegetable mixture into a food processor; add the egg whites and cornstarch. Pulse the filling until it holds together.
Lay a wonton wrapper on the counter. Brush the surface with the beaten egg white. Drop 1 tablespoon of the mixture onto the center of the wrapper. Fold it in half to make a semicircle and crimp the edges to seal. With the seam side up, tap the bottom lightly on the counter to flatten the base. Repeat with the remaining wrappers and filling.
Lightly oil the bottom of a 10-inch bamboo steamer and line it with whole cabbage leaves. Stand the dumplings in the steamer in a single layer and donâ€™t let them touch. You should be able to get 12 dumplings in the steamer at a time. Bring 1 to 2 inches of water to a boil in a wok. Set the bamboo steamer inside the wok; then cover it with the bamboo lid. Steam for 10 to 12 minutes, until the dumplings feel firm. Serve with one of the dipping sauces on page 128. These also work great as hors dâ€™oeuvres for a cocktail party.
Edited: October 9th, 2009