Get your steamer heating up to a rolling boil.
Crumble the tempeh by hand to as fine a texture as you can into a large bowl. Add the onion, ginger, garlic, soy sauce, salt, coriander, and rice flour. Mix until everything is thoroughly combined.
Form heaped ½ tablespoon balls and roll them with your hands into 1 inch-ish spheres. You’ll end up with somewhere around 25 by the time you’re finished. Line your steamer with a liner or greaseproof paper and arrange the balls inside, with some space between them. Steam for 20 minutes.
The balls will be very sticky to the eye and touch right when they're finishing steaming, so leave them to cool for a further 20 minutes before the next step.
Heat a well seasoned wok (or sturdy frying pan with nonstick qualities that can take high heat) to medium high for a couple minutes. Once it’s hot, add the oil. When it begins to smoke, add the balls and stir fry for a few minutes until they have some browned spots on most sides. Remove them to a plate.