For the batter, whisk together the plain flour, cornflour, lager, ale, and curry powder until smooth, before seasoning well with salt and pepper.
Trim the cod cheeks, and pat dry with kitchen paper. Then dust each piece of cheek in seasoned flour and dip in the batter to coat. Gently lower each piece into the deep-fryer and fry until the fish is floating and the batter is golden, this should take 3–5 minutes depending on the thickness of the cheek.
Dice all ingredients and combine, and then put in the fridge until ready for plating.
Soak the breadcrumbs in milk. Meanwhile, blend the garlic with the roe, mustard, salt, and water in a food processor.
Drain the breadcrumbs and then add them to the food processor. Blend the mixture, slowly adding the grapeseed oil a little at a time, then add the olive oil.
Squeeze in the lemon juice and blend. Season to taste with white pepper, and then pour the mixture into a bowl, cover with cling film and refrigerate until needed
Bring all the ingredients to boil, and then add the agar agar. Boil for a further minute then remove from the heat. Cool the mixture in the fridge until it sets, then blend it into a gel.
Combine all the ingredients for the salt mix in a bowl. Clean and trim any sinew from the cod fillets. Sprinkle a layer of salt mix on a long piece of cling film, lay the cod on top and cover with the rest of the salt mix.
Roll the cod tightly in the cling film and press between two heavy trays for 1 hour. Turn the fish over and press for a further 1 hour. Rinse off the salt in ice water and pat dry with kitchen paper. Remove the skin and roll tightly in cling film again. Using a sharp knife, portion the cod into 4 x 50g pieces. Poach the cod in a water bath at 50°C for 9 minutes.
Stack cod skins on top of each other. It should be around 3 cm in height. Vacuum pack the skins and steam for 30 minutes. Put the steamed bag in the freezer. When frozen, remove skins from bag and cut the skins into 1mm slices. Dehydrate at 65°C until dry. Deep-fry the skins to make them puffy and crispy. Season with kelp powder and serve.
Bring the water to boil, and then add the salt and vinegar. Cut the potatoes with an apple corer and then blanch in the salt and vinegar water for 5 minutes until soft. Leave to air dry before blanching at 160°c for 3 minutes, then finish at 180°c for another 3 minutes until the potatoes are golden.
Bring a pan of salted water to the boil, and then add the bicarb. Then drop the peas in for 1 minute before removing them from the heat. Blend them and pass them through a sieve then season and put into the fridge until ready to serve.