Mix together pork, green onions, cilantro, ginger, mushrooms, soy sauce, sesame oil, sugar, cornstarch and egg white in a large bowl until well combined.
Working with 6 wrappers at a time, use fingertip to wet edges of each wrapper with water.
Top each wrapper with 2 teaspoons pork mixture.
Bring the 4 corners up towards the top of the filling, pleat the sides of the wrapper to form a cup, and press the wrapper snugly around the filling. The dumpling does not need to be fully enclosed at the top.
Keep the dumplings covered with dampened tea towel while working.
Place a bamboo steamer in a large pot and add enough water to come just below the base of the bottom steamer.
Line each basket with a single layer of cabbage leaves to prevent the dumplings from sticking; important, do not omit or you will be eating of the steamer :).
Place a single layer of dumplings on top of leaves.
Cover and simmer for 8 minutes or until pork is cooked through; do not overcook.
Serve warm with Spicy Lime Dipping Sauce or other dip.