1. Combine the flour, cornflour, baking powder, salt, pepper and turmeric in a large bowl, reserving about one and a half tbsps of the mixture and set aside.
2. Pour beer and water into the bowl and whisk until you have a smooth, lump-free batter. Leave to rest for 30 mins.
3. Meanwhile prepare the chips. Boil a large pan of water, add the cut potatoes and boil for 2-3 mins until the outsides are tender but not soft.
4. Drain potatoes then tip on to a large baking tray with flour, 2tbsp oil and salt and pepper. Toss until all the potatoes are evenly coated. Set aside.
5. Pat the fish dry with kitchen paper, then season with salt, pepper and lemon pepper for extra flavour. Then coat evenly in the remaining turmeric flour mix. Shake off excess then dip into the batter.
6. Heat 1 ltr oil in a deep saucepan. When hot enough, lower each fillet into the hot oil and fry until golden and crisp. Using a slotted spoon, lift out the fish and drain on kitchen paper. Sprinkle with salt.
7. Fry the potatoes until crisp and lightly golden. Remove from oil and drain on kitchen towel. Sprinkle with salt and vinegar. Serve with fish and enjoy!