Toast the pine nuts in a pan, the oven or microwave. (see notes) Transfer to the food processor immediately to cool. Add parmesan cheese, lemon juice, and garlic. Blend until finely ground. Add fresh basil pulse again.
While your food processor is running, slowly pour in the olive oil through the feed tube. Scrape down the sides as you go. Blend until everything is smooth and nicely combined, leave some flecks of basil for beauty! If your mixture is too thick, you can thin it out with more olive oil if necessary.

Taste test your pesto creation. Adjust seasonings to your personal preferences, with extra salt or pepper. You can also throw in a bit more Parm, basil or garlic to get the consistency and flavor just right.

Serve immediately or store in an airtight container. To store, pour a thin layer of olive oil on top to prevent oxidation and browning. Cover the top of the container with plastic wrap. Press gently on the surface to remove air. Refrigerate. Keeps well for up to 1 week. You can also freeze pesto sauce in an ice cube tray or in spoonfuls on a tray. Transfer to a freezer bag once frozen. Thaw the exact portion you need later on.