There isn't a surfeit of choices expressly for vegetarians/vegans in Cairo, but all things considered this is a great one. It's simple, fast, tasty, extremely filling, and cheap. And it's in Cairo!!
I went a couple of times for lunch during my visit to Egypt and it definitely sets you up for the rest of the day. Plus it's kind of a landmark, so be sure to go.Pros: Tasty, Inexpensive, It's in Egypt.