Soak the bread in a little water for 10 minutes or so, then squeeze out the excess. Put into a mortar or food processor with the walnuts and garlic and pound or blend.
Stir in the olive oil, cream, Parmesan and seasoning to make a thick creamy sauce.
Cook the pasta in plenty of boiling salted water until al dente. Mix 2tbsp of the pasta cooking water with the sauce, then drain the pasta.
Toss the pasta with the sauce and the parsley and serve immediately.