Here's the stuff that we know about Cavolo Nero...
A loose-leafed cabbage from Tuscany, Italy. The leaves are a very dark green, almost black, hence its name, which translates as 'black cabbage'. It has a pleasantly tangy, bitter flavour, with a sweet aftertaste. Some people spell this 'cavalo nero'.
How do I get Cavolo Nero ready to use?
Remove old or damaged outer leaves, cut the leaves free of the core and slice out any tough central stalks. Rinse, then chop or slice.
What about keeping Cavolo Nero?
It will keep in a cool, dark place or the vegetable drawer of the fridge for several days.