I was making pesto one day and couldn't find the lid to my food processor. So first I tried mixing it all in a blender. Didn't work, the leaves wouldn't go down to meet the blade. I had this pastey pesto at the bottom and full leaves on top. Transferred it to the magic bullet thinking the blender (it's a really old blender) was just busted. Same thing.
This frustration prompted me to find the food processor lid once and for all. I did and put everything in processor and worked like a charm.
Why can't you make pesto in a blender? What's the difference in the design of a food processor and blender?