-Toast 1/3 cup raw green pumpkin seeds in a heavy skillet over medium heat, stirring frequently until golden and puffed, about 4 minutes.
-Put 1 large garlic clove in a food processor and process until well chopped.
-Add ½ tsp salt, ¼ tsp black pepper and the leaves from 1 bunch of flat leaf parsley.
-Pulse until well chopped and add ¼ cup grated Parmigiano-Reggiano and the toasted pumpkin seeds.
-Process until seeds are finely chopped.
-With the motor running add 1/3 cup olive oil in a slow steady stream.
To serve with pasta: Put the pesto in a large bowl.
-Cook 1# of spaghetti until al dente.
-Whisk about ½ cup of the pasta water into the pesto.
-Drain pasta then toss with pesto, adding salt and pepper to taste.