Gingery pork and shiitake dumplings

Instructions

1. Soak mushrooms in 1/2 cup cold water until softened, about 30 minutes. Drain; squeeze dry. Cut and discard stems; mince caps to yield about 1/2 cup.
2. Combine pork, celery or water chestnuts, scallions, and mushrooms in a medium bowl. Add cornstarch, rice wine, soy sauce, ginger, oil, sugar, salt, pepper, and egg whites; stir to combine.
3. Holding a dumpling wrapper in one hand, spread 1 Tbsp pork filling onto the wrapper, leaving an 1/8-inch border. As you fill dumplings, set them on a parchment-lined work surface lightly dusted with cornstarch. (Place remaining wonton wrappers in a plastic bag so they don’t dry out.)
4. With the dumpling in one hand, use your other hand to begin gathering and folding in the outer edges of the wrapper around the filling, mostly enclosing it, but leaving an opening at the top. Stand filled dumpling on parchment and continue filling remaining wrappers, covering finished dumplings with a dry kitchen towel to prevent drying.
5. Place finished dumplings in a bamboo or metal steamer basket lined with 2-3 cabbage leaves. The dumplings should be in a single layer, 1/2-inch apart and 1 inch from the edge of the steamer basket. (The size of your steamer will determine how many dumplings can be cooked at one time.)
6. Place basket in steamer over boiling water. Cover and steam on high until pork is cooked through and wonton wrappers are translucent, 5-7 minutes. Carefully remove dumplings from steamer. Repeat with remaining dumplings, replenishing cabbage leaves and boiling water, as needed. Serve immediately.