Step by step
1 Sift 225gm (1½ cups) self-raising flour and 75gm (½ cup) cornflour into a large bowl. Gradually whisk in 375ml (1½ cups) chilled beer and 60ml (¼ cup) chilled soda water to form a thin batter. Season with salt.
2 Preheat vegetable oil in a deep-fryer or large saucepan over medium-high heat to 200°C (see note).
3 Using a sharp knife, cut 1kg skinless firm white fish fillets (we used blue-eye trevalla) into 8 long-even pieces then toss in plain flour, shaking off any excess.
4 Dip fish fillets in batter and drain off any excess.
5 Gently lower battered fish into oil being careful not to create a splash; cook for 4 minutes or until golden and just cooked through.
6 Remove fish from oil with tongs and drain on paper towel. Season with salt and serve with hand-cut chips, tartare sauce and a lemon cheek.