The Gemoro speaks about eating vegetables during Shemitta.
What about the Issue MiDerabonon of S'fichim?
(Maybe they were harvested before Shemitta started and stored, but then the same could be done for garden vegetables!)
The Yerushalmi writes (Bava Basra 5:1) "All Sefichim are Asur except for those which grow in a fallow field, a plowed field, in a vineyard field, and in a grain field". These are the "Sadeh" vegetables mentioned in the Gemara. (See Ramban, Parashas Behar, for an explanation of this Yerushalmi.)
Gmar Chasimah Tovah