I was called by Subway to work. I had just recently got hired by another company part time and wanted another part time job. The manager needed someone with a more flexible schedule. Considering I made above Min. Wage at my part time job I wasn't to upset.

Very simple and straightforward. Normal questions like availability, have you worked in food service before, etc. I think it depends on location though since friends at other locations have had more substantive or less substantive interviews.