In a large mixing bowl, sift in the flour & cornflour. Add the salt & paprika then mix.
Create a well in the middle & pour in the beer. Whisk well until a smooth batter forms. Cover & refrigerate for 30 mins.
Preheat the oven to 200C. Add the chips to a large baking tray & drizzle with olive oil until well coated.
Add a generous pinch salt & the dried herbs. Toss then bake for 40 mins until crispy.
Pour the vegetable oil in a large deep pan until a third full. Heat on a high temperature until hot - test temperature by adding a small piece of bread, it should go golden & crispy in 10 seconds.
When the oil is ready, remove the batter from the fridge then dunk a few cod pieces into the batter. Toss until well coated then add to the oil.
Fry each piece for 3-5 mins each side until golden & crispy. Remove & let rest on kitchen towel. Repeat with remaining pieces.
To assemble, add 1-2tsp of tartare sauce per taco then lettuce, rocket, cucumber, chips, fish & pickled red onion. Finish with a squeeze of lemon