Place half of the olive oil in a blender or food processor followed by the arugula, Parmesan, and pecans. Pulse until everything begins to combine and drizzle in additional olive oil until it is thoroughly blended to a creamy consistency.
Taste for seasoning before adding salt as the Parmesan can often be quite salty by itself.
Toss pesto with hot pasta, add fresh cracked black pepper and garnish shaved Parmesan.
Notes
My arugula pesto will keep in the fridge for 2-3 days, and it freezes perfectly for up to 30 days.
Recipe by My Earth Garden at http://www.myearthgarden.com/2011/12/arugula-pesto/