We are travelling with a young family so nothing too posh nor too rough!
If you are looking for local Egyptian food there is a famous vegeterian plate called Koshari which is a blend of macaroni, rice, lentils served with hot sauce, many places offer it such as Abu Tarek resturant, El Omda Restaurant these are affordable restuarants, if you are looking for a higher scale restuarant you can try Abu El Sid restuarant which provides a typical Egyptian food http://www.egyptholidaysdirectory.com/listing/abu-el-sid-egyptian-restaurant-and-bar-721.html
or another famous restaurant is taboula which serves lebaneese mezza among the menu there is alot of vegeterian plates about 11 years ago
Definitely would recommend Taboula which is just behind the British Embassy. Has a fantastic meze selection with lots of vegetarian options and was very reasonable.
Another good place was Felfella - again, good decent food at a great price. about 11 years ago