Place 3 tablespoons pine nuts, spinach, and next 6 ingredients in a food processor.
Process or blend until smooth, scraping sides of processor bowl once.
Slowly add water and oil to the processor until well blended. Set mixture aside.
Cook linguine and potato in boiling water 6 minutes.
Cook additional 5 minutes or until potato is tender.
Drain. Combine mixture with remaining 3 tablespoons pine nuts, spinach mixture, and pasta mixture in a large bowl.
Toss well to coat.
Sprinkle with Parmesan cheese (optional).