Clean and cook the mussels and cockles without any extra liquid. When they open, discard the shells and any that are unopened. Reserve the sieved cooking liquor.
Cook the prawns in salted boiling water. When the water starts to bubble again, strain and plunge into cold water. This stops the prawns from overcooking. Remove the shells.
Cut the squid into fine rings.
Finely chop the onion and garlic, and fry in the olive oil until golden. Add the squid and cook gently for a few minutes. Add the cooking liquor and wine and let it reduce over brisk heat until it forms a glaze. Add the rest of the shellfish, parsley, wine, chilli and pepper. Check if salt is necessary.
Cook the tagliatelle in abundant salted water until al dente. Strain, mix in the seafood sauce and sprinkle with finely chopped parsley. Serve at once.
© 1993 Ann and Franco Taruschio. All rights reserved.