Using your processor pulse the basil, garlic and pine nuts.
Slowly add the olive oil in a constant stream while the food processor is on.
Stop to scrape down the sides of the food processor with a rubber spatula.
Add the grated Parmeasn cheese and lemon juice; pulse again until blended.
Add salt and freshly ground black pepper.
Store pesto in a jar or airtight container in the refrigerator for about a week, or in the freezer for about six months.
Keep it looking fresh and green by covering the top with a thin layer of olive oil or with a sheet of plastic wrap directly on its surface; this will keep it from oxidizing and turning brown. If your pesto darkens in color, it will still taste good.
I freeze it by dropping Tablespoons of it on a parchment paper, freezing it and storing in a zip lock bag in the freezer.