In a bowl, combine chicken mince, spring onions, ginger, garlic, soy sauce, sesame oil, oyster sauce, shredded cabbage, sugar, MSG, black pepper, and salt if needed.
Mix well until fully combined and slightly sticky.
Spread a thin layer of the chicken mince mixture directly onto the bottom of the pan.
Place one dumpling wrapper over the chicken layer.
Add another thin layer of chicken mince on top of the wrapper.
Continue layering in this order: chicken mince → wrapper → chicken mince → wrapper, until all the filling and wrappers are used.
Finish with a dumpling wrapper on top.
Add ¼ cup water to the pan around the edges.
Cover with a lid and cook on medium-low heat for 8–10 minutes until the filling is fully cooked and wrappers are tender.
In a small bowl, mix soy sauce, sesame oil, vinegar, and sugar.
Stir until sugar dissolves.
Drizzle the sauce over the cooked dumpling layers.
Top with chilli oil and chopped spring onions.
Slice and serve warm.