Dunno. The story of how the sammie came to be is cute: According to John, "One winter, a fella drove in with a load of potatoes. He brought a few of 'em over to the restaurant to see if they were frozen. I fried the potatoes on our grill and they looked pretty good. A few of our customers asked for them, so I put the potatoes on their sandwiches." And the rest is history. The Primanti Sandwich: a true taste of Pittsburgh.
