The first time I read the instruction “strip the cavolo nero”, I took it to mean that I should cut it into strips. So I gathered a few leaves into a bundle, then cut across the lot, forming thick ribbons before continuing to cook whatever it was I was making, which might have been soup. I prepared cavolo nero like this for years. Until, that is, I watched a cookery demonstration at a country festival in Umbria where the chef demonstrating held a stem of cavolo in one hand, then, with the other, clasped the leaf and pulled, separating the tough midrib from the bubbly green.
Now, for anyone familiar with cavolo nero, I am no doubt describing a logical and completely obvious preparation. For me, though, on a cold Sunday near Perugia, he was a magician and I was an idiot.