Place 3 tablespoons pine nuts, spinach, and next 6 ingredients (spinach through garlic) in a food processor; process until smooth, scraping sides of processor bowl once. With food processor on, slowly pour water and oil through food chute; process until well-blended. Set aside.
Cook linguine and potato in boiling water 6 minutes. Add green beans; cook an additional 5 minutes or until potato is tender. Drain. Combine remaining 3 tablespoons pine nuts, spinach mixture, and pasta mixture in a large bowl. Toss well to coat. Garnish with Parmesan cheese, if desired.