Thanks, Roger, but that's all Greek to me.
Actually, the service started a few years ago, although I think maybe there wasn't a lot of demand (or maybe people couldn't figure out their website?) and the route ceased for a while:
Astra Airlines flying twice a week from Thessaloniki to Kefalonia during the summer. Not the most user-friendly website I've ever come across but you might be able to find more info on astra-airlines.gr
Let's see if it, er, takes off this time.