Mix soy sauce, vinegar, chilli oil, sesame oil, sugar, garlic and ginger in a small bowl.
Slice the scallions lengthwise and add to cold water with the coriander.
Fry the dumplings in a bit of oil until golden brown, add ¼ cup of water and steam with a lid for 5 minutes.
Add tomatoes, dumplings, greens and sesame seeds to a large bowl.
Toss with the sauce!
