Boil the vegetable broth in a large cooking pot.
Put-in the onions and simmer for 10 minutes.
Meanwhile, make the fish paste by combining the fish fillet, tapioca starch, salt, and pepper in a food processor. Mince the mixture until the texture becomes soft.
Transfer the mixture in a mixing bowl. Add the minced scallions and ice cubes. Mix well using your hands until the mixture becomes thick.
Make a ball out of the mixture by grabbing a handful using your hand. Make an “O” shaped opening using your thumb and index finger. Gently squeeze your hand until the mixture exits the opening. Use a spoon to scoop the mixture.
Place the scooped mixture in the simmering broth. Continue to simmer until the balls float.
Add the chopped scallions and bok choy. Cook for 5 to 7 minutes.
Pour in the fish sauce. Stir.
Transfer to a serving bowl.
Serve. Share and enjoy!