It's the simplest thing in the world. Very fast, amazingly delicious. Fresh, healthy, all good things.
First clean and trim your arugula. Then throw it into a food processor. Add in a good sized handful of pecans, 1 quarter cup grated Parmesan, and enough olive oil to give everything a good shine. Blend it up, and if you find that it isn't coming together, add piping hot water one teaspoon full at a time until you get a consistency that begs to be put on pasta. For a kick, you can dump in some hot pepper, or for more Italian style, stick with some garlic.
More food-processor ideas? Add arugula to homemade hummus instead of cilantro or parsley.