In a large mixing bowl, combine the ground chicken, chopped cabbage, green onions, minced ginger, minced garlic, and finely chopped mushrooms. Add baking soda if desired. Drizzle in sesame oil, rice vinegar, oyster sauce, and soy sauce, mixing thoroughly until all ingredients are well incorporated.

Begin assembling by placing a spoonful of the filling at the bottom of each ramekin, covering with a wonton wrapper. Repeat the process, creating layers until the ramekins are nearly full.

Carefully pour about ⅓ cup of water into each filled ramekin, then top with two additional wonton wrappers.

Place the ramekins into a Dutch oven, ensuring the water level reaches halfway up the sides of the ramekins. Cover and steam for approximately 20 minutes.

Once done, carefully remove the ramekins using tongs. Drizzle with chili oil and garnish with sliced green onions. Serve warm.