In a blender place the arugula, basil, olive oil, garlic, lemon, and salt. Process until smooth and not stringy.
Next add in the parmesan and pecans. Pulse until you acheive the desired consistancy. I like to have larger chunks of pecans in my pesto. If you prefer the consistancy be more smooth, allow the mixture to blend longer. However, Don’t over-blend, causing the cheese to melt from the heat of the blades.