Peel the potatoes and cut into large, thick chips.
Then rinse and dry using kitchen towel.
Fry the chips in the oil until soft but not coloured - about 3 mins.
Drain and shake the chips well and set to one side.
Put some flour onto a plate and coat the fish fillets thoroughly.
To make the batter, put the flour, bicarbonate of soda, salt and pepper into a bowl then gradually add the bitter.
Stop when you have a thick coating of batter.
Whisk until smooth and add the lemon juice, then mix again thoroughly.
Take one fillet of haddock at a time, holding it by its end and swirling it around the batter until it has a good coating, then plunge it into the hot fat immediately.
As soon as the first fillet has started to crisp, add the rest one at a time, taking out the first ones as they cook.
This should take 6-10 mins depending on thickness of fillet.
Place on a baking tray and keep warm in the oven.
While the fish is in the oven, add your chips to the hot fat again and cook until crisp and golden.
Recipe by appetite magazine at https://www.appetitemag.co.uk/black-sheep-best-bitter-battered-fish-and-chips/