Steam the Brussels sprouts for about 15 minutes until soft.
In a bowl, whisk together the ingredients for the batter. In a second bowl, combine the ingredients for the breading.
Heat the frying oil in a pot or wok (add enough so that the Brussels sprouts can swim in the oil, but don't fill the pot more than half full).
Dip each Brussels sprout first into the batter, then in the breading and carefully lower it into the hot frying oil. It should only take 1-2 minutes for them to get a crispy and golden outer layer. Transfer them to a plate lined with kitchen paper to remove excess oil.