Caldo verde

• By Daphne Caruana Galizia

Caldo verde is popular throughout Portugal, but you cannot escape it in Porto. It's made from kale, a robust curly-leaved cabbage variety with a long stem, which prefers northern climates. Up until the end of the Middle Ages, kale was the most common green vegetable in the whole of Europe. In Scotland, it was so fundamental to the diet that in colloquial Scots the word is synonymous with food. To be off your kale is to be too ill to eat. In the European diet, kale has been replaced gradually by other members of the brassica family and by salad greens, except in north-western Germany, where a whole culture has apparently grown up around it, with kale days, kale dinners, kale tours, and even a kale king of the kale festival. Every kitchen garden there has kale growing in it. Its advantage is that it freezes well – we brought some back with us to make caldo verde – and it actually tastes better after being exposed to frost. In Porto, kale is sold in street markets and greengrocers, and in the main food market, there are women who shred it ready to make the soup, using special machines. You can make caldo verde by using the outer leaves of a cabbage or the younger leaves of kohlrabi (ġidra). They should be shredded using the coleslaw setting of a food processor.

For 4 people, you will need:

200g of cabbage leaves/kale (finely shredded), one onion (peeled but left whole), two cloves of garlic (peeled but whole), 600g of good potatoes (peeled but whole), four slices of chourico (available at good supermarkets), two slices of crusty bread, olive oil, salt.

Put the potatoes, garlic and onion in 1.5 litres of water with a pinch of salt and a generous splash of olive oil. Bring them to the boil, turn down the heat, and leave the pan to simmer until the potatoes are very soft. Mash them well into the onion and garlic, still in the water, using a potato masher. Bring the pan to the boil again and leave the mixture to simmer a while longer. Just before you serve the soup, turn up the heat again, bring it to a rolling boil, put in the shredded cabbage, turn down the heat after a couple of minutes, and leave it to simmer for around 15 minutes. Add black pepper to taste, and another dash of olive oil. Place a slice of chourico in each soup-plate and pour the soup over it.