Cook the pasta in boiling salted water until al dente.
Meanwhile heat the olive oil in a frypan and cook the onion until softened, about five minutes. Add wine and garlic and reduce the liquid a bit. Add cream, prawns and mussels. Season with salt and pepper.
Drain the pasta and put in bowls and top with the seafood. You can also serve this with grated cheese if you like, or chopped chives.