Ask someone to name five vegetables, they'll name mostly plants with a very short life-cycle, like carrots, cabbage, lettuce, etc. These are grand aul vegetables, nothing wrong with them, but there's an interesting class called perennials that live much longer, live for years.
The advantage of these is labour; you just plant them once and they're good for a long time.
I've had great success in Ireland growing skirret (cearraċán in Irish, Latin binomial sium sisarum) and hablitzia tomnoides.
Perennial Vegetables by Eric Toensmeier is the one to read about this.