In a medium skillet, toast the pine nuts over medium heat for about 5 minutes, stirring frequently. Be careful not to burn them. Cool slightly.
Peel the garlic cloves by smashing them with a flat side of the knife.
In a large (14-cup) food processor, place the basil leaves, pine nuts, garlic and salt.
Process it until smooth.
While the processor is still running, slowly add olive oil.
Add grated parmesan and process for another 30 seconds or so.
Fresh pesto should be refrigerated in an airtight container for up to 1 week.
There're 2 ways you can freeze your pesto sauce.
Pour the prepared pesto into a freezer bag, squeeze all the air out and flatten it. It’s easier to break a small chunk out, or defrost it, when it’s nice and flat like that.
Divide the pesto into ice cube tray, or this silicone mold (<- I prefer this mold, because it makes bigger pesto chunks). Once frozen completely transfer the pesto cubes into a large freezer bag to store. The frozen pesto is good for up to 6 months.