1.Combine egg and the water in medium bowl; mix in flour until just combined, but still lumpy.
2.Heat oil in large saucepan.
3.Halve bananas lengthways. Working in batches, dip banana in batter; deep-fry bananas until crisp and golden. Drain on absorbent paper; sprinkle with sugar.
4.Serve bananas immediately, with matcha (green tea) ice-cream, if you like.