Step 1

Sift the flour and baking powder into a bowl and stir in the salt. Make a well in the centre and gradually whisk in the beer (or sparkling water) to make a smooth and thick batter – it should be the consistency of double cream.

Step 2

Heat the oil in a large deep pan or deep fat fryer to 180°C/350°F. Dip two of the fillets in the batter to coat then gently lower into the hot oil. Fry for 6-7 mins until the batter is crisp and golden brown. Drain thoroughly on kitchen paper and keep warm while frying the remaining fish fillets.