For the mustard mayonnaise

• • • Egg 1, or 2 egg yolks
    • White wine vinegar 2 tsp
    • Salt ½ tsp
    • Oil 300ml, sunflower or olive

For the fish and chips

• • Plain flour 240g
  • Baking powder 3½ tsp
  • Ice-cold water 270ml
  • Floury potatoes 900g
  • Sunflower oil for deep frying
  • Thick cod fillets 4 x 175g
  • Salt and pepper to season

For the tartare sauce

• Green olives 1 tsp, finely chopped
• Gherkins 1 tsp, finely chopped
• Capers 1 tsp, finely chopped
• Chives 2 tsp, chopped
• Parsley 2 tsp, chopped
• Mustard mayonnaise half the prepared quantity

1. To make the tartare sauce in a machine: put the whole egg, vinegar and salt into a liquidiser or food processor. Turn on the machine and then slowly add the oil through the hole in the lid until you have a thick emulsion.
2. To make the batter, mix the flour, 1 tsp of salt and the baking powder with the water. Keep cold and use within 20 minutes of making.
3. Pre-heat the oven to 150ºc/gas 2. Line a baking tray with plenty of kitchen paper and set aside.
4. Peel the potatoes and cut them lengthways into chips 1 cm thick. Pour some sunflower oil into a large deep pan until it is about a third full and heat it to 130ºc. Drop half the chips into a frying basket and cook them for about 5 minutes, until tender when pierced with the tip of a knife but not coloured. Lift them out and drain off the excess oil. Repeat with the rest of the chips and set aside.
5. To fry the fish, heat the oil to 160ºc. Season the cod fillets with salt and pepper and then dip into the batter. Fry, 2 pieces at a time, for 7–8 minutes, until crisp and golden brown. Lift out and drain on the paper-lined tray. Keep hot in the oven while you cook the other 2 pieces.
6. Raise the temperature of the oil to 190ºc and cook the chips in small batches for about 2 minutes, until they are crisp and golden. Lift them out of the pan and given them a shake to remove the excess oil, then drain on kitchen paper and keep them hot while you cook the rest. Sprinkle with salt and serve them with the deep-fried cod.

From Rick Stein’s Seafood published by BBC Books, photo by Rebecca Bernstein.