This is a salty-sweet version (think Greek cheesecake) of the Greek Patsavouropita, created by bakeries as a way of using up old scraps of filo pastry: the ”old rags” indicated by the title. They’d just go along their counters, collect up all the bits and turn them into this pie. For this reason, you don’t need to worry about keeping your filo covered as you go, as is normally advised. It doesn’t matter if it dries out a little as you make it, indeed this can even be desirable. I have made this with a variety of filo pastries, and I have found that the more widely available brands are too damp and too heavily sprinkled with flour to do the job well. Luckily, those brands make a frozen filo, which doesn’t seem to suffer from the same problems, which is why I stipulate this, below. However, should you be lucky enough to have access to good quality, authentic filo, then please use fresh. And please read the Additional Information section at the end of the recipe before proceeding. For US cup measures, use the toggle at the top of the ingredients list.