In a small skillet, heat the pine nuts over a medium heat. Stir continually. The pine nuts are done when they're lightly golden brown. Heating them intensifies their delicious flavor.
In a food processor, combine pine nuts, spinach, parmesan cheese, garlic, and about 1/2 cup of olive oil. Pulse until the mixture is smooth and evenly pureed. You might need to scrape the sides several times to get the perfect consistency.
Pour the pesto into a glass or stainless steel bowl. Add more olive oil until you've reached the desired consistency. Add essential oils and stir with a stainless steel spoon.
Serve immediately or chill, if desired. Serve in ceramic or glass dishes.
You can make this pesto ahead of time and store in a canning jar in the refrigerator for at least a week. You might want to stir in a little more olive oil when you're ready to serve.