Arugula Mayonnaise

Biscuit says this stuff is addictive - and I'll take her word on anything. She found the recipe at epicurious and has used it on just about every sandwich she's made since. At the epicurious site, they use it in a smoked turkey sandwich, with extra (whole) arugula leaves on the turkey slices. Posted here so I can find it when I need to make it. :-)