For the lobster tapioca garnish, place the tapioca in a pan with the lobster stock and heat until the tapioca becomes translucent. At this point, remove the tapioca from the heat and drain off the liquid into a container. Taste the tapioca and add salt as required. Add a little of the cooking liquid back to the tapioca and spread the mix evenly over a silicon mat and dry in a dehydrator or a very low oven until crisp (this will take a few hours).
For the garnish, snap off a few pieces of the tapioca crisp and fry in oil until crisp and puffed up. Set aside until ready to serve.
To make the pasta, in a food processor, mix the flour and egg yolks until they come together to form a rough dough. Squeeze a piece of the dough, if it feels hard add some more egg yolk and mix again. The dough should be firm but pliable.
Tip the dough out onto a lightly floured work surface and knead the dough for five minutes. Wrap in cling film and place in the fridge to rest for 30 minutes.
For the crab mousse, put the salmon and egg white into a food processor and pulse until smooth then slowly add the cream, pulsing to combine. Transfer the mousse to a bowl and add the picked white crab meat, chopped dill and chopped ginger. Season, to taste, with salt and pepper. Spoon the mousse into a piping bag fitted with a large plain nozzle and set aside.
Take the pasta out of the fridge and cut it into two pieces. Put the dough through the pasta machine one setting at a time, starting at the largest and working down to the last and smallest setting. Put the other piece through the machine. You now have two long sheets of pasta.
Brush one pasta sheet with some egg yolk and pipe four equally-sized balls of the crab mousse, about 6cm/2½in apart, in a line along one side of the pasta. Lower the other sheet of pasta over the mousse and gently pat it down using your fingers to seal all around the each ball of filling.
Using a 4-6cm/2-3in cutter, cut out the ravioli into neat rounds.
For the mussels, clean and debeard the mussels. If any mussels are opened, tap them lightly on a hard surface. If they don't close, discard them.
Heat a heavy-bottomed pan and add the mussels. Cover with a lid. After a minute, add the shallots, garlic, thyme and the white wine. Replace the lid and steam the mussels until they are all open (discard any that don't open). Add the cream and bring to a boil. Strain the mussels, reserving the sauce and leave to cool slightly until safe to handle and pick out the mussel meat from the shells.
Add the mussel meat, diced cooked potatoes and chives to the cream sauce and warm through. In a separate pan wilt the spinach with two tablespoons of water and a little salt. Keep warm until ready to serve.
To serve, bring a pan of salted water to a simmer and add the ravioli. Cook for four minutes.
Place a small mound of the wilted spinach into the centre of each serving bowl then spoon over the mussel and potato sauce. Remove the ravioli from the water using a slotted spoon and place one on top of each mound of spinach. Using a hand-held blender, foam the rest of the mussel sauce and spoon it around the ravioli.
Top the ravioli with caviar and tapioca crisps then garnish with some pea shoots and serve immediately.