Sift flour and a pinch of salt into a large bowl. Make a well in centre and pour in egg and beer or soda water. Gradually combine with a wooden spoon, until a smooth batter forms. Rest for 30 minutes. Cut potatoes lengthways into 7mm-wide strips. Place in a bowl of iced water until ready to cook.

Line a baking tray with paper towel. Pour oil into a deep, heavy-based saucepan or electric deep-fryer. Heat oil to 180°C or test by dipping a chip into oil (if bubbles appear instantly, oil is hot enough). Drain and dry chips thoroughly. Using a wire basket, perforated spoon or wire skimmer, lower chips into oil and cook in batches for 8 minutes, until tender but not golden. Remove from oil and drain on paper towel.

Reheat oil to 185°C. Lower chips back into oil straight away. Cook for 2-3 minutes, until crisp and golden. Drain on paper towel, sprinkle with salt and set aside in a warm place.

Pat dry fish fillets with paper towel. Reheat oil. Stir batter. Coat fish in flour then batter, letting excess drip off. Lower fish into oil and cook for 3-5 minutes, until batter is golden. Drain on paper towel, season with salt and serve with hot chips and lemon wedges.