Add the sunflower seeds, grated dairy free parmesan, salt, and lemon zest (if using) to a small food processor.
Process the seeds and cheese until it looks like coarse crumbs.
Add the fresh basil and garlic to the food processor and process again until the basil is finely chopped.
Turn on the processor and while the processor is running, pour the oil into the processor, stopping to scrape down the sides as needed so everything gets processed evenly.
Process until you're happy with the texture of your pesto.
Store in an airtight container in the fridge for up to 3 days. Or freeze in an ice tray to make pesto cubes you can thaw and add to your favorite dish.