Pat the fish dry and place on chopping board.
With a sharp knife, make three diagonal slits into side of fish, then repeat in the opposite direction to create a diamond pattern.
Turn the fish and repeat on the other side.
Lightly toss garfish in a little flour to coat.
Meanwhile, heat oil in a hot wok until a slight ripple effect occurs on surface of oil, carefully add garfish and shallow fry in batches for about 3 minutes or until golden brown.
When cooked, the flesh should be white on the inside, not transparent.
Remove from wok and drain on absorbent paper.
Add chillies to same hot oil and fry until a deep, bright red colour, remove with slotted spoon and drain well.
Arrange garfish on platter and garnish with combined coriander, shallots and fried chillies.
Serve immediately with bowls of lemon wedges and Szechuan pepper and salt.