Set up a smoker with chips and place it over a medium heat.
Score the whole mackerel, rub it with 1 teaspoon grapeseed oil, season it generously with salt and place it in the smoking compartment along with the bones from the two filleted mackerel.
Smoke it for 10 minutes, turn the mackerel for a further 10 minutes or until, when gently prized, the flesh lifts away from the bones.
Add the two native oysters to the smoker for the last 2 minutes.
Remove the mackerel and oysters, place the oysters in a bowl with 1 teaspoon of lemon oil and set aside in the fridge.
Once rested at room temperature for 5 minutes carefully lift the skin off the mackerel and remove the meat from the bones. Pick through the mackerel to ensure no small bones remain.
Grate the horseradish into the mackerel, add the capers, celery salt, lemon juice and crème fraîche and gently fold to create a loose and textured pâte. Set aside covered in the fridge.
To make the muffins mix the flour and salt in a food mixer.
Warm the milk, sugar, butter and yeast.
Add to the flour, knead to a smooth dough, transfer it to a fresh bowl and set aside in a warm place to proved for 1 hour.
Knock it back, lightly dust the work surface with the cornmeal, roll the dough out to a thickness of 1cm, cut it into 4cm discs, allow to prove for 10 minutes and then gently toast in a dry, non stick pan for 5 minutes either side or until the muffins are golden and cooked through.
Set aside covered with a cloth.
Skin the mackerel fillets and dice them into ½cm dice. Set aside in the fridge.
Peel the cucumber, cut it into ½ cm slices, cut out any seeds and dice. Sprinkle with salt, set aside for ½ hour.
Rinse thoroughly, squeeze it out and then season it with the vinegar and sugar and set aside.
Place the oysters, egg yolk, mustard and lemon juice and ice cube into a blender and blend to a smooth purée.
Gradually add the grapeseed oil to create a light oyster mayonnaise. Set aside in the fridge.
Sweat the onion, leek and celery in the lemon oil. Cover with 500ml water, bring to the boil and simmer for 20 minutes.
Pass through a fine sieve, add the reserved oyster juice and season with salt.
Add the sosa elastic powder, whisk vigorously to combine, return to the boil, simmer for 1 minute and pour the liquid onto a flat baking sheet, set aside until the liquid has set.
Cut 2 × 15cm squares from the gel, interlace with parchment paper and set aside in the fridge.
Mix 100g of diced mackerel with 60g oyster cream. Add the capers, cucumber, chives and set aside.
Trim the upper loin of the two mackerel fillets and set aside in the fridge.
Cook the new potatoes in salted water until tender, allow them to cool, peel them, cut into a ½cm dice and set aside.
Whisk the egg yolk, mustard and lemon juice briefly. Add a pinch of salt and pepper and while whisking vigorously drizzle in the grapeseed oil to form a mayonnaise. Set aside.
Heat up a heavy based pan, add a splash of water followed by the mussels and winkles.
Cover with a lid and steam for 1 minute or until the mussels have opened. Drain the shellfish, reserving any liquor.
Remove the mussels from the shell, pick the winkles from their shells and trim the tiny hard disc from their ‘feet’. Set aside, covered in their juices.
Whisk together the flour with half of the beer. Add the sugar, salt and yeast and whisk to a smooth paste. Add the remaining beer, whisk until homogenous and set aside in a warm place. Mix the diced potato with enough mayonnaise to bind. Add the spring onions. Blanch the samphire in boiling water for 10 seconds. Refresh, drain and chill.
Sweat half the onion, leek and celery with half of the butter and a pinch of salt.
Add to the smoked mackerel bones, cover with the milk and water, bring to the boil and simmer for 20 minutes.
Pass through a colander and then through a fine conical sieve.
Sweat the remaining vegetables and the potato in the remaining butter, with a pinch of salt until tender. Add the milk, bring to the boil and cook for 10 minutes. Transfer to a blender and blend to a smooth, velvety velouté.
Prize one muffin in half and lightly toast.
Gently warm the two smoked oysters through under a warm light or grill.
Heat up the soup to near boiling point.
Lay out the two sheets of jelly, place the tartare in the centre, fold the jelly over and set aside.
Spoon a small quantity of smoked mackerel pâte onto each piece of muffin, top with a smoked oyster and set aside.
Season the mackerel filets for the salad, brush lightly with oil and grill, skin side up, under a hot grill until cooked.
Dip the mussels into the beer batter to lightly coat them and deep fry until golden. Warm the winkles through in 2 teaspoons of their juice, add the lemon oil and set aside.
Place a small spoon of the potato salad onto a plate.
Add some samphire and top with a piece of mackerel.
Drizzle with the winkle vinaigrette and top with the mussel beignets.
Add a mackerel tartare jelly to each plate.
Blend the velouté to aerate it and serve it, on the side, in a cup. Drizzle with the remaining lemon oil.