Method

• 1.
  Place the flour, 1 teaspoon sea salt and some freshly cracked black pepper into a large bowl, and make a well in the centre. Slowly start pouring the beer into the well, whisking to combine, until all the beer is added and a smooth batter forms. Strain batter through a fine sieve to remove any small lumps of flour. Place in the fridge for 1 hour.
• 2.
  Dry the potatoes with kitchen paper and cut lengthways into chips about 1cm-thick. Half fill a deep-fryer or large heavy-based saucepan with oil and heat to 160°C. (If you don't have a deep-fryer thermometer, test a cube of bread - it will turn golden in 30 seconds if the oil is hot enough.) Fry chips in batches for 5-7 minutes or until soft but still pale, then drain. The chips can be prepared to this stage ahead of time.

• 3.
  Preheat oven to 170°C. When you are ready to cook the fish, increase the temperature of the oil to 190°C (a cube of bread will turn golden in 15 seconds). Fry chips again, in batches, for a further 2-3 minutes or until crisp and golden. Drain on kitchen paper. Keep warm in the oven.
• 4.
  Maintain the oil temperature at 190°C. Dust the flathead fillets in the extra flour. Dip into batter, one at a time, allowing excess to drain off. Carefully place into the hot oil. Depending on the size of your fryer, cook fish in batches. Fry for 3-4 minutes or until golden brown and crisp, then drain on kitchen paper.
• 5.
  Remove chips from oven. Sprinkle fish and chips with salt. Serve with wedges of lemon and tartare sauce.