Mix all the ingredients together in a food processor with a normal blade.
Turn the dough out onto the counter and use your hands to shape it into a ball and draw together any crumbs.
Wrap in cling film and leave to relax in a cool place for an hour.
For the Filling
Remove the prawns from their shells.
Put the crabmeat and prawns in the food processor and whiz until smooth.
Add the egg white, lemon juice salt and pepper and whiz again until just mixed.
Stir in the chives, cover and set aside.
For the sauce/bisque
Heat the oil in a heavy saucepan and fry all the shells and onion until they start to brown.
Add the garlic and cook for another 30 seconds.
Now add the brandy, tomatoes, bay leaf, tomato puree, star anise, and stock. Simmer for 20 minutes.
Strain the sauce and reduce to 150 ml by boiling rapidly.
Add the cream; reduce to the consistency of single cream and season to taste. Set aside.
Preparing the Ravioli
Roll out your pasta dough as thinly as possible using a pasta maker, about 6 inches.
Cut strips about 6 inches in width. Place teaspoonfuls of the filling in even rows at intervals of 1 1/2 inches over half of the pasta. Fold the other half over the mounds of filling and press together, firmed around each mound to squeez out all the air.
Cut between the rows, making sure the edges are sealed. You can use a fork to decorate the edges.
Cook the ravioli in boiling water for 3-4 minutes until al dente.
Place on the serving dish, drizzle over the sauce and decorate with the chives.