- 225g/8oz dried marrowfat peas
- 1 tsp bicarbonate of soda
- 25g/1oz butter
- sea salt and freshly ground black pepper
- 1 lemon, cut into wedges
- 200g/7oz plain flour
- 15g/½oz fresh yeast
- pinch salt
- pinch caster sugar
- 200ml/7fl oz beer
- 1 tbsp cider vinegar
- vegetable oil, for deep frying
- 4 x 200g/7oz hake fillet, skin on, pin boned and trimmed
- 1 onion, sliced into rings
- 4 slices thick white bread
- butter, for the bread, optional
- 3 free-range egg yolks
- 1 tbsp Dijon mustard
- 2 tbsp cider vinegar
- 300ml/11fl oz rapeseed oil
- 50g/1¾oz capers
- 75g/2½oz gherkins, chopped
- 1 shallot, finely chopped
- 1 small bunch dill, chopped
- 2 tbsp chopped flatleaf parsley
- ½ lemon, juice only
- For the mushy peas, soak the peas in a large bowl, in three times their volume of water for at least 1½ hours or, if you have the time, overnight.
- Drain the peas, rinse under the tap, and place on the stove in a large pan and cover with the water. Add the bicarbonate of soda. Cover and bring to the boil and once boiled, reduce the heat and simmer the peas for 1½-2 hours, stirring from time to time.
- The peas should be soft and mushy in texture but not too dry. If they are wet, continue cooking over the heat with the lid off to dry out a little. Beat in the butter and season with salt and pepper.
- For the beer battered hake, combine the flour, yeast, salt and sugar in a bowl.
- Add the beer and vinegar and whisk until it forms a thick batter.
- Set aside to ferment for about 30 minutes. It is ready to use when the mixture starts to bubble.
- Heat a deep fat fryer to 190C/375F or heat the oil for deep-frying in a deep heavy-based frying pan until a breadcrumb sizzles and turns brown when dropped into it. (CAUTION: Hot oil can be dangerous. Do not leave unattended.)
- Dip each piece of onion into the batter to coat thoroughly. Cook them in batches in the fat fryer, and cook for 2-3 minutes until golden-brown and cooked through.
- Dip each piece of fish into the batter to coat thoroughly. Lower them carefully into the fryer, and cook one at a time. Cook for 4-6 minutes until the fish is cooked through and the batter is golden-brown.
- Drizzle the remaining batter into the fat to make scraps.
- Butter the bread with the softened butter and cut in half.
- For rapeseed tartare sauce, whisk together the egg yolks, mustard and vinegar in a bowl or small processor.
- Still whisking, start adding the rapeseed oil very slowly to make a mayonnaise – the mixture should be thick and light once the oil is incorporated.
- Stir in the capers, gherkins, shallot and herbs.
- Season with salt and pepper and a touch of lemon juice.
- To serve, place the fish on plates, with a spoonful of mushy peas alongside. Pile the bread and butter next to it and finish with a squeeze of lemon juice and spoonful of tartare sauce.