I've worked in this area for about a year and always find myself in this dilemma of finding a decent lunch. There aren't many options it seems. I'll go to the Atrium if I have cash on me and its nice enough to walk, or the "mall" in L'Enfant plaza and either get Au Bon Pain or go to Oh's for their orange chicken. When I have the time I'll occasionally go down to Chinatown or the Naval Archives and either go to Ella's pizza, Five Guys, Chipotle, Fuddruckers or Potbelly's. I have on occasion walked to the Capitol area and gone to Cosi as well as taken the Metro to Pentagon City. And got a sandwich from the Holiday Inn which was good.
I typically eat at my desk so carry out is important and don't have a preference for style. I typically eat sandwiches but am open to new things especially pasta or rice bowls.
Also I was wondering if anybody knew if you could do carry out at Kaz, I've been wanting to try their Bento box for a while now.