Being called for Jury Duty is not fun at all, and to make matters worse you're there all day. The courthouse is located on 360 Adams Street in downtown Brooklyn and if you search 'Kosher' into Google Maps, the only result you will get within a 20 minute walking radius is a closed Pizza shop.
They gave us a 1 hour lunch break and I was starving, so I did what any Jew would do in this situation, find another Jew! I asked the first orthodox looking man, and turns out he frequents the area alot. He directed me to a kosher shack in the lobby of a building across the street.
He has coffee, pareve Chulent, and fresh soups which are the only hot items he sells. He also has a variety of cold platters and sandwiches. Including tuna, cheese, turkey, pastrami, bread and others.
The hashgacha checked out, although I forget specifically which one it was. The food was actually pretty good.
Considering there are 30-40 Jews who serve on Jury Duty every day, and at least another few hundred working in the area I'm surprised this is all I was able to find nearby.