Cheap places to eat out in London

Am working near the delights of Whitcross Street market for the next fortnight, which means i'll be spunking a lot of cash at the food vans.

Having only worked in the vicinity briefly before, I only got to try the Hoxton falafel stall, which was ace. Any reccommendations peeps? I've heard the Burrito van is awesome.

The salad place for the best salad in the world! £3.50 with cheese and olives and everything under the sun!