I mentioned over dinner at my parents house (about 20 years ago) that I'd read that running 240v through a gherkin would cause it to glow - and pretty much as soon as dinner was over, my father and I had the experiment set up.

Gherkins and even pickled onions glowed brilliantly. I set up a basic site to share the video we'd taken and details of the experiment, and shared it to B3ta. Sadly all lost to time.