1. Soak the clams in salted water for 2 hours. Rinse and set aside. Rinse and scrub the mussels. Chop the onions and garlic. Cut the tomatoes into wedges.

2. In a large pot, cook the mussels and clams over medium heat. Remove them with a slotted spoon. Strain the broth and return it to the pot to reduce by half.

3. In a pan, heat 4 tbsp (2 fl oz) of oil. Add the onion, garlic, oregano, and tomatoes. Season with salt and cook over medium heat for 10 minutes.

4. After 8 minutes, add the shrimp, stir, then add the shellfish and reserved broth.

5. Cook the spaghetti in a large quantity of salted water until al dente. Drain.

6. Transfer the spaghetti to a large serving dish. Add the remaining oil, seafood, and broth, and several grinds of pepper. Mix, sprinkle with chopped parsley.