In a food processor, pulse spinach, basil and green onion until mostly pureed.
Add avocado, parmesan, garlic, salt, and lemon juice. Pulse until combined and pureed.
Rinse and drain 1 can of great northern beans. Add to the food processor and pulse until the entire mixture is well pureed, scraping the sides as needed. Add a little extra liquid from the can or water if necessary.
This dip is best served cold. Refrigerate for a few hours before serving. The flavors deepen the longer it sits in the fridge and so it can even be made the day before you want to serve it. Enjoy!