Ingredients:

  • 2 large russet potatoes (about 600g/1.3 lbs), peeled and cut into 1/2-inch thick chips
  • Vegetable oil, for deep frying (about 4 cups/1 litre)
  • Sea salt flakes, to taste
  • Malt vinegar, for serving (optional)
  • 1 cup (125g) all-purpose flour, plus extra for dusting
  • 1 teaspoon baking powder
  • 1/2 teaspoon salt
  • 1/2 cup (120ml) ice-cold beer (lager or pale ale works best), plus more if needed
  • 1/4 cup (60ml) ice-cold sparkling water
  • 2 (6-8 ounce/170-225g each) cod fillets, skinless and boneless, patted dry
  • All-purpose flour, for dusting (reserved from batter ingredients)
  • Salt and freshly ground black pepper, to taste

Instructions:

  1. Soak the cut chips in cold water for at least 30 minutes (or up to a few hours) to remove excess starch. Drain well and pat completely dry.
  2. Heat the oil to 275°F (135°C). Fry the chips in batches until softened but not browned, about 5-7 minutes. Remove and drain on a wire rack.
  3. Whisk together the flour, baking powder, and salt in a bowl. Gradually whisk in the beer and sparkling water until just combined. Don't overmix; a few lumps are okay. Chill the batter for at least 15 minutes.
  4. Increase the oil temperature to 375°F (190°C). Fry the chips again in batches until golden brown and crispy, about 3-5 minutes. Remove and drain on a wire rack. Season immediately with sea salt.
  5. Season the fish fillets with salt and pepper. Lightly dust with flour, shaking off any excess.
  6. Heat the oil to 350°F (175°C). Dip each fish fillet in the chilled batter, ensuring it is fully coated. Carefully lower the fish into the hot oil.
  7. Fry the fish until golden brown and cooked through, about 4-6 minutes, turning once. The batter should be crispy and the fish should flake easily with a fork.
  8. Remove the fish from the oil and drain on a wire rack. Season lightly with salt. Serve immediately with the chips, malt vinegar (if desired), and your choice of sides.