Sweet potato, cavolo nero and Gruyère lasagne

This isn’t the sort of dish you’ll want to knock up on the spur of the moment, as there are quite a few steps involved, but you can make it the day before and then gently reheat it in time for lunch or dinner. Cavolo nero is a lovely Italian green veg, although its name translates as ‘black cabbage’. I like to use Gruyère or Jarlsberg in lasagne, as they give an unexpected twist to the flavour, although any good firm tasty cheese, or even a sharp goats’ cheese, will be delicious. Serve this