Spaghetti with Lemon and toasted walnuts

1 cup walnut halves
1/2 cup finely grated Parmesan cheese
1/4 cup olive oil
1/4 cup lemon juice
2 teaspoons grated organic lemon zest
1 clove minced garlic
1/4 teaspoons freshly ground black pepper
1 pound spaghetti
1 cup coarsely chopped Italian parsley

Oven should be preheated to 350 degrees Walnuts should be toasted for 10 minutes on a baking sheet. Coarsely chop the walnuts after they cool
The cheese, oil, lemon juice, lemon zest, garlic and pepper should be whisked together in large bowl.
Pasta should be cooked according to package directions Drain the pasta and save 1/2 cup of the water that the pasta cooking. The drained pasta should be added to cheese mixture, and to combine it toss it and add pasta water if it mixture is too thick. Parsley and walnuts should be stirred in  and it should b seasoned more salt and pepper  if you want.