Method

1. For the rye bread and butter, place the flour, sugar and salt in a large bowl or a food mixer fitted with a dough hook. Pour 200ml/7fl oz tepid water into a jug and sprinkle over the yeast, mixing to combine. Gradually add the yeasted water to the dry ingredients, mixing continuously, until all of the yeasted water has been incorporated. Add another 150ml/5fl oz water and mix until it comes together as a dough.

2. Turn the dough out onto a lightly floured work surface and knead well for 5-10 minutes, or until smooth and elastic. Roll the dough into a long sausage shape, then transfer to a baking tray lined with baking parchment, cover loosely with cling film, and set aside to prove for at least 6 hours, but preferably overnight, until the dough has doubled in size.

3. When the dough has proved, preheat the oven to 220C/200C Fan/Gas 7. Uncover the dough and dust with a little rye flour, then slash the top diagonally a few times using a sharp knife. Bake the loaf in the oven for 30 minutes, or until golden-brown and the base sounds hollow when tapped firmly. Set aside to cool slightly.

4. Meanwhile, blend the softened butter in a food processor until pale and fluffy, then transfer to a serving dish.

5. For the fruits de mer, steam the langoustines, razor clams and clams for 5-8 minutes, or until cooked through (discard any clams that do not open during cooking). To do this you can place the different ingredients into separate layers of a steamer and suspend the stack over a pan half-filled with boiling water. Alternatively, steam each ingredient separately using a steamer insert. Set aside.

6. Cut the lobster in half lengthways and remove the legs and claws. Discard the head contents, leaving just the body meat. Crack the lobster claws and knuckles by bashing them with a rolling pin, then pick out the meat and pile it back into the body shell.

7. Open the shell of the crab and discard the dead man’s fingers (the sponge-like gills). Remove the claws and crack by bashing them with a rolling pin. Pick out the meat and pile it back into the crab shell.

8. For the mayonnaise, whisk the egg yolks, mustard, vinegar and lemon juice in a bowl until well combined. Gradually add the oil in a thin stream, whisking continuously, until it has all been incorporated into the mixture to form a thick mayonnaise. Stir in the lemon zest and season, to taste, with salt and freshly ground black pepper.

9. To serve, pile the seafood, including the oysters and shrimps, onto a large serving platter. Serve the lemon mayonnaise and whipped butter in bowls alongside, with the sliced rye bread.