For the pickled onions
For the tartare sauce
- STEP 1
First, make the pickled onions. Put the vinegar in a pan with 150ml water, the coriander seeds, peppercorns, sugar and 1 tsp salt over a medium heat, stirring until the sugar has dissolved. Scoop the onions into a bowl and carefully pour over the hot pickling liquid. Leave to cool for 15 mins, then cover and chill for at least 1 hr. Will keep chilled for up to two days.
- STEP 2
For the tartare sauce, mix together all the ingredients, then cover and chill. Will keep chilled for up to two days.
- STEP 3
Sift the flour and cornflour into a bowl, then stir through the salt. Make a well in the centre and whisk in the cold beer to make a smooth batter. Cover and chill for 30 mins.
- STEP 4
Heat the oil in a deep, heavy-based pan, no more than two-thirds full, until the oil reaches 190C on a cooking thermometer. If you don’t have a thermometer, check the oil is ready by dropping a small cube of bread into the oil – it should turn brown in about 10 seconds.
- STEP 5
Dip each piece of cod into the batter to fully coat, then gently shake off the excess. Fry the fish in batches for 4 mins per batch, then remove using a slotted spoon and drain on kitchen paper.
- STEP 6
Warm your tortillas in a low oven or in a dry frying pan. Spread over the tartare sauce, then add the fish and top with the pickled onions and shredded lettuce, plus a dash of hot sauce, if you like. Best enjoyed with a cold beer.