I have been making this salad since I was in my 20's. It comes from an old Sunset Southwest Cookbook that has been a mainstay in my kitchen for a long time. It has a lot of great recipes that I used when living in Arizona.
The key to this salad is the cumin vinaigrette. There is something about how it works with the sugar and salt to make this one of the most awesome salads ever. A girl once told me she could live off of this dish and nothing else :). I put it together again a few weeks ago and it turned out great as usual.