Don't try to make this pesto in a food processor. The processor just throws it around the bowl. A blender does a much better job. Be sure to thin the pesto with some of the hot pasta water before tossing it with pasta. If your pesto typically turns army green shortly after you make it, you'll appreciate the beauty of this version. I blanch the basil briefly to set the color, and I add a pinch of powdered ascorbic acid (vitamin C), which keeps the pesto from oxidizing.