For the filling: In a bowl, combine the ground chicken, shiitake mushrooms, Chinese celery, ginger, cornstarch, rice wine, soy sauce, chicken bouillon, salt, sesame oil, white pepper and egg white. Mix well and set aside.
For the wontons: Line a baking sheet with parchment paper and dust lightly with cornstarch. Take 1 wonton wrapper and place 1 teaspoon of the filling in the center. Gather up the sides and mold them around the filling, making a ball shape and twisting the top to secure. Repeat with the remaining wrappers, lining them up on the prepared baking sheet.
Drop the wontons into large pot of boiling water and cook until they float to the top, 3 to 5 minutes.
To serve: Place six hot wontons on each serving dish. Surround the wontons with chopped cucumbers. Drizzle with Zhenjiang Vinegar Sauce and top with chopped cilantro.
For the vinegar sauce: In a bowl, stir together the chile oil, soy sauce, Sichuan peppercorns, sesame oil and Zhenjiang vinegar.
Recipe courtesy of Ching-He Huang