Add the onion, ginger and garlic to a food processor and blend until the mixture verges on forming a rough paste (alternatively, mince everything by hand). Add the kale and pulse until incorporated with no large chunks remaining. Add the tofu and pulse until roughly incorporated. Add the rest of the ingredients and blend until desired consistency, using a spatula to scrape down the sides and incorporate everything evenly.
Fill a small bowl with water and flour a clean surface for rolling your dough. Roll tablespoon-sized balls of dough into a circle, then place a rounded ½ tablespoon of filling in the middle Use your finger to dab water around half of the wrapper’s edge and fold over to form a half moon; pinch the edges to seal.
Once all the dumplings are prepared, you can either (1) boil all the dumplings, and then fry them or (2) do them simultaneously.
To boil and fry simultaneously:
Set a pot of salted water to boil over medium heat and a frying pan over medium heat. Once boiling, add a few dumplings to the pot (don't overcrowd the water) and boil for 2-3 minutes, until dumpling skin starts to look translucent and no longer raw.
As soon as dumplings are done boiling, add a bit of sesame or olive oil to the frying pan and transfer the dumplings to the pan--they should start to sizzle when they hit the pan. Cook for 2-3 minutes, or until a golden crust starts to develop on the bottom. Flip and cook for another 1-2 minutes, so a crust forms on the other side. Eat IMMEDIATELY.