I find myself in this general area once a month or so, and I'm always looking for new inexpensive lunch options. For a quick bite I love Julia's; I'm also really impressed with Couscous Cafe. Nan and Beyond is on my to-try list. For some reason I keep not trying Yuca, though. Is it worthwhile? Anything else near there worth trying?
And not to discourage your good suggestions, but I think I've hit everything I'm interested in north of N St. I walk to Dupont pretty frequently. Now I'm searching to the south. Many thanks.