It might seem crazy to be making a thick, hearty soup in the midst of Christmas madness, but I have the advantage that I’m not actually ‘doing’ Christmas until Boxing Day. It all came about because I couldn’t resist buying a bundle of cavolo nero (black cabbage) at the farmers’ market yesterday, where I’d gone to buy Brussels sprouts for the Christmas meal. I love cavolo nero and will cook it just as a vegetable with a meal, but it always makes me think of Ribollita, the wonderful Tuscan soup that’s a meal in itself.

The Tuscans are fabulous at creating great ways of using up stale bread, and soup is one of the ways they do it, Ribollita in the winter and Pappa al Pomodoro (tomato and bread soup), which I ate in Florence in the summer; also Panzanella (bread and tomato salad). I didn’t actually have stale bread; I had a gorgeous fresh sourdough from my local Italian bakery, but that wasn’t a good enough reason for putting off making the soup.

Ribollita isn’t an exact recipe. A bit of research gave me two entirely different looking soups from Nigel Slater (a red soup) to Jamie Oliver’s green soup. It’s basically a leftovers soup – leftover bread and leftover vegetables – but fairly standard are the inclusion of cavolo nero, beans and, of course, the bread. Both Nigel and Jamie added tomatoes too, in the form of a can of tomatoes, which I went with too. ‘Ribollita’ means ‘reboiled’ and the soup is traditionally made in advance, best eaten a day after cooking, and may be topped up with extra leftovers over days. This reminds me of visiting one of my authors in Italy in the late 1970s. I was editing lots of cookery books and visited Robin Howe, a prolific and well-respected cookery writer of the time, while holidaying in Italy. She and her husband lived in Liguria, with glorious views across the Mediterranean from their hillside apartment, and I stayed for a couple of days. I remember her adding leftovers to the soup simmering on her stove and being slightly uncertain about a soup that may have been started a few days before and constantly reheated and added to. But it tasted delicious – and I came to understand it was very Italian!

I stripped the leaves from my bunch of cavolo nero. Jamie adds the stalks, finely sliced, but I decided against that. Put them in a big bowl of water to wash and remove any grit, drain well and then slice fairly finely.

Chop 1 large onion, 2 medium carrots and 1 stalk of celery. Try to chop fairly evenly as the soup isn’t blended and it will look nicer if the vegetables are much the same size. Gently cook the mixture in some extra virgin olive oil in a large pan. Cook for about 20 minutes until soft but not browned, stirring frequently to prevent sticking. The careful cooking of your soffrito is the base of a good flavour for your soup. Once it has softened, add 1 large clove of garlic, crushed.

Stir and cook for another minute or two, then tip in 1 x 400g tin of plum tomatoes.

Stir to combine and then tip in 1 x 400g tin of cannellini beans (drained), add a couple of bay leaves, season with some salt and freshly ground black pepper. Mix together and then put a lid on the pan and cook gently for about 20 minutes.

Cut 2 thick slices from a sourdough loaf (if you don’t have this, just a good loaf – but supermarket sliced bread really won’t do!). Break the bread into smallish pieces and add to the soup. Stir in.

Now tip in the sliced cavolo nero. It will look like far too much but it soon wilts down. Stir round until it’s mixed and add some water (or vegetable stock) so that the vegetables are almost, but not quite, covered.

Bring to a simmer and cook gently for about half an hour.

Remove the bay leaves and check the seasoning. Thin it down a little if necessary, but remember it’s supposed to be very thick – more like a stew than a soup. Now it’s ready. If you can possibly resist eating it until the next day, it will taste all the better for 24 hours maturing.

To serve, spoon into a bowl and grate over a generous amount of Parmesan. Drizzle some extra virgin olive oil over the top. You could serve extra bread on the side, but it doesn’t really need it with the bread soaked into the soup.

I ate some straight away. It hadn’t been my intention for supper but I couldn’t resist it! And it tasted so wonderful that if it’s even better tomorrow, then great. Tomorrow will be a fairly quiet Christmas Day with my son and his family (though possibly not that quiet if almost-3-year old Freddie gets very excited about the presents under the Christmas tree), with Jonathan cooking steak for our meal. Then more family arrive on Boxing Day, which will see 9 of us enjoying the traditional Christmas meal of turkey and Christmas pudding.

A very happy Christmas to you all!