1. Bring a pot of water to the boil and add fettuccine and cook till al dente. 2. Heat butter in a pan and add finely diced onion and garlic, sauté till transparent. 3. Add seafood including peeled prawns and debearded and scrubbed mussels and cook till tender. 4. Add wine and reduce by half. 5. Add cream and again reduce by half. 6. Add basil and season to taste. 7. Strain fettuccine and toss through marinara serve with fresh basil leaves.