For food & drink, Greek Cooking Class at The Greek Kitchen delivers.
The Greek Kitchen is the version of this that consistently earns 'highlight of the trip' reviews — instructors like Vasia and Thanasis run it with real humour, and the dishes reach a touch beyond the autopilot menu (imam bayildi as well as the tzatziki), with an optional Varvakeios market stop first. It's a sociable afternoon that turns into a long shared lunch and a take-home skill. The catch: it still eats a half-day, and the core recipes are crowd-pleasers you could learn from a good cookbook.