I live in the Tampa Bay area. Locally, the Greek salad comes with a scoop of potato salad in the center. Is this the practice in any other areas?
As far as I know this is a very local practice. It originated with Pappas' restaurant in Tarpon Springs (now in other places as well). The Pappas' potato salad is a simple one, the potatos doused w/vinegar, mixed with chopped scallions and mayonnaise, lots of salt, little pepper. I have no idea the why of this but am sure of the where: Tarpon Springs, the huge Greek community.
Just recently I had a Greek salad in Ft. Lauderdale and it had potato salad and I remarked to my husband, "The restaurant owner must be from Tampa." It's the first time I've ever seen it served that way not in the Tampa area.
They do it in Lake County also, but I've never seen it outside this area. I am inclined to agree it's a spinoff of Pappas style . . .