Cook the peas in a pot of boiling salted water for 1 minute. Immediately immerse the peas in a bowl of ice cold water, and drain when fully cooled.
To assemble, place the spinach leaves in a salad bowl. Sprinkle the peas and pignolis over the spinach. Add the pesto and toss.
Place the walnuts, pignolis, and garlic in the bowl of a food processor fitted with a steel blade. Process for 30 seconds. Add the basil leaves, salt, and pepper. With the processor running, slowly pour the olive oil into the bowl through the feed tube and process until the pesto is finely pureed. Add the Parmesan and puree for a minute. Serve, or store the pesto in the refrigerator or freezer with a thin film of olive oil on top.
Notes & Tips
To toast pignolis, place them in a dry saute pan and cook over medium heat for about 4 minutes, until evenly browned, tossing frequently.