Pulse the garlic in a food processor for a few seconds.
Then, add the basil, sunflower seeds, and lemon juice, and pulse until it is coarsely chopped.
Next, drizzle in the olive oil and and blend until smooth. (If you choose to freeze the pesto without the cheese, stop after this step and freeze it now.)
Add the mixture to a bowl, then mix in the parmesan. Add extra olive oil as needed to achieve your desired consistency.
Give the pesto a taste, and add salt and pepper as needed. Enjoy!