Be cautious because the link is not a TNT (not tried by me anyway) recipe...it's just the only one I could find and the poster is trying to replicate a secret recipe.
Here is a link to mikespastry.com if you want to order them and have them shipped....only problem is that they're quite pricey...$15 per pound plus shipping.
mikespastry: Pistachio Nut (Mike's Own) Macaroons by the Pound
I'm going to make these myself and probably tweak* the recipe so I'll let you know how it goes.
*...for instance, the recipe says to take a level Tblsp of the dough and roll into balls...um, that is a miniscule amount for making a cookie...and I don't think they were rolled into balls as they aren't that uniform in shape. The instructions forget to mention to coat them in powdered sugar after baking