Chill skrei fillets in fridge till required.
PASTA DOUGH
Put the flour and nori into the robot coupe, pulse in the eggs, little bit at a time, and stop soon as the mix comes together. You might not need all the eggs, and if you accidently add too much, add a little flour. Tip the mix out on to a floured surface, and knead 3-5minutes, until smooth. Divide in half, wrap in clingfilm and chill.
LANGOUSTINE TORTELLINI'S
Bring a large pan of salted water to the boil, blanch the langoustines for one and a half minutes, and chill in iced water, or till cold. Remove the shell form the tails, crack the claws, and remove any meat from them, discard the head. Finely chop the tails and claw meat, place into a bowl, add the breadcrumbs, and mix in the cream to bind. Season with salt, little lemon juice, and shape them into 8 small balls, chill till needed.
Roll the pasta dough, through a pasta machine, starting from the widest setting, and gradually going down to its thinnest setting. The pasta should be dry, but no cracks (go easy on the flour) slightly elastic, when pulled, and a slight shine. Cut into 8 discs with a 6-7 cm cutter, place a langoustine ball in the middle of each, and brush the edges with the beaten egg. Fold the top half over though ball, sealing the edges, and making sure there is no air in the semi circle. (You need to be quick; pasta will dry out, do one at a time, and keep the pasta discs under a damp cloth). Then carefully press the bottom onto a flat surface so the tortellini supports its own weight. Dip in melted butter, and place on a tray which has been lined with greaseproof, chill till needed.