– Add basil, spinach, nuts, garlic, salt, lemon zest, lemon juice, olive oil, and water to a food processor. Blend until the pesto is smooth. Stop and scrape down the sides and bottom and blend again several times to make sure everything is well incorporated.
– Once pesto is smooth, blend in parmesan cheese. If the pesto is very thick add another splash of water and blend again. Taste the pesto and add additional salt and pepper as desired.
– Enjoy immediately or store in the fridge or freezer.