Place the pine nuts into a small, dry 8-inch skillet and heat over medium. Gently toss the nuts occasionally until they are fragrant and lightly golden. About 5 to 6 minutes. Transfer the toasted nuts to a plate to cool.
Meanwhile, remove the stems from the spinach and coarsely chop. Wash and pat dry with paper towels. (I use my salad spinner for this, works like a champ!) Measure 2 cups and place into the bowl of your food processor.
Next add in the garlic, cooled pine nuts, cheese, salt and pepper. Secure the lid and pulse until coarsely chopped. Add in the olive oil and pulse until smooth. For a loose pesto add more olive oil.
Store in a glass jar, cover with a thin layer of olive oil before securing a tight-fitting lid and storing in the refrigerator for 2 to 3 months. Add another layer of olive oil after each use.