Bring a large pot of salted water to a boil and cook the pasta according to pack instructions. We suggest leaving them al dente and pouring cold water over them once done to stop the cooking process.
Meanwhile, heat the oil in a large frying pan over medium heat. Cook the prawns for one minute on each side until pink. Remove and set aside. Add the onion and cook for 30 secs-1 min, then add the garlic and cook until golden. Stir in the tomatoes. Add half the parsley.
Pour in the wine, then leave to bubble until reduced by half. Add the mussels, and cover to steam for a few minutes until all the mussels are open.
Add the cream to the pan and cook for 1-2 minutes to soften. Add the seafood mix and cook for 1-2 minutes or until thoroughly heated.
Drain the cooked pasta, reserving about a cupful of the cooking water. Return the pasta to the empty pan and tip in the seafood and tomato mixture. Add a little of the pasta cooking water to loosen, then toss together until everything is well mixed, adding more water as needed.
Divide between serving dishes and sprinkle over the rest of the chopped parsley and the parmesan. Serve with a lemon wedge to squeeze over.