You could also Tony's New York pizza/Italian food on Liberia ave.

I don't know if they do that kind of single-meal catering/delivery - I've only had them for event catering and I've had lunch at their deli - but everything I've had is terrific and the chef is very friendly. If they can help you out, I'd highly recommend them. He is located in Old Town Manassas.

http://otcaterer.com/index.html
Old Town Caterer & Deli

I have a friend who just has a baby in Manassas. She is a single mom and I'd love to send me some meals. I don't live in that area of the DMV and while I am planning to visit, I'd like to have some food (not a fruit basket or baked goods) delivered to help her out. Does anyone know of a catering company, deli, etc that will delivery trays to Manassas?