Looking for inspiration...

If you like beetroot, you could grow some in there. I grow some in a polytunnel and they do a lot better than outside. I start in modules and then plant out about 4" apart in groups of 2 or 3 then start eating the thinnings some weeks later. Carrots seem to miss the worst of the fly if I grow some under cover. A box of salad leaves would grow quickly under cover.

Don't eat many salads (I know I should do) and I still have beetroot on the plot. I harvest as I fancy some.