Bring a large pot of salted water to a boil. Add the walnuts and cook for 5 minutes. Remove the nuts, let them cool, pat dry, and rub them in a cotton towel in order to remove as much of their skin as possible.
Soak the bread in milk. When soggy, squeeze the milk back into the bowl where it was soaked. Set the bread and milk aside.
Place the walnuts in a food processor (or use a mortar and pestle), along with the pine nuts, garlic, marjoram and bread, with some salt. Blend together until a thick paste is formed. Add some of the retained milk until a thick, creamy consistency is achieved. Add more salt to taste. Remove the mixture to a bowl, and drizzle in the olive oil, and then mix in the Parmigiano. Add more of the retained milk if necessary to achieve a creamy consistency.
Bring another large pot of salted water to a boil.
Cook the pasta until al dente (about 2 minutes less than the package directions), drain, and reserve 1 cup of the cooking water. Place the pasta in a serving bowl and slowly mix in the nut sauce. Add a bit of the reserved cooking water if it seems too dry.