To make the broth, place all of the ingredients and 1 litre/1¾ pints water in a large saucepan and cook over a medium heat for 20 minutes. Set aside.
To make the seafood, discard any mussels with broken shells and any that refuse to close when tapped. Place a large saucepan on the hob over a medium heat, add the mussels, wine, bay leaf, thyme, shallot and garlic and cook until the mussels are opened. Discard any mussels that remain closed.
Strain the mussels and reserve the mussels and the cooking liquor. Strain the cooking liquor and pick the mussels from their shells. Set aside.
To make the spaghetti, heat the oil in a large frying pan and add the garlic and chilli. Add the passata and cook for a few minutes.
Add the spaghettini, spreading it across the base of the pan. Leave undisturbed to start caramelising for 1–2 minutes.
Gradually add ladles of the broth and reserved mussel liquor until all of the liquid absorbed and the pasta is cooked through.
Stir in the mussels, prawns and squid and serve.
