Cardoons

I have to accept that one of my seed-grown artichokes is actually a cardoon. Last year I hoped and hoped, but when it made two plus metres and produced abundant tiny (but pretty) flowers I had to admit that this was no artichoke!
A quick interweb suggests the plants need to be harvested in late summer or early autumn, or another from December to spring! A friend from Provence says that they eat it as a gratin at Christmas, which fits with the winter harvest.
So, anyone grown, and more importantly cooked and eaten cardoons?

   

The beast in the summer last year. And now of course, instead of one giant there are three fighting for space!