Preheat the oven to 350°F. Spread the pine nuts onto a baking sheet. Toast in the oven for 6-7 minutes until golden then set aside to cool.
In a large food processor place the pine nuts, spinach, basil, onion, shredded cheese, lemon juice, lemon zest, sea salt, garlic cloves, pepper and red pepper flakes.
Pulse a few times to process.
Drizzle the olive oil in through the tube at the top. Stop and scrape the side of the bowl at least once so that everything blends together.
Use immediately tossed over warm pasta, as a spread for toasted garlic bread or as a dip.
Chill tightly covered in the refrigerator for up to 2 days.
Notes
Walnuts may in place of the pine nuts, if desired.
Pine Nuts can also be toasted in a skillet on the stove top. Move the pan continually and toast over medium-high heat until fragrant.