Found on Food for Thought
They recommend doing this in a food processor. I had to use a blender because I am not the lucky owner of a big enough food processor (mine only holds maybe 1/2 cup of anything). Sigh.... :)
3 cups of packed basil leaves (washed and stems removed)
2/3 cup pine nuts
2/3 cup grated parmesan cheese
3-4 cloves garlic, peeled
kosher salt and freshly ground pepper
olive oil - enough to allow it to blend freely, but not be soupy
Place all of these ingredients in a food processor and drizzle a generous amount of oil on top. Pulse several times until it is coarsely chopped, adding more oil as necessary. Pulse a few more times until it is finely chopped.