“In this dish, it’s important to use really good olive oil. If you can’t get any, then use the best you have but half the amount shown here. Think of olive oil as a feature ingredient, not just a staple. The better your oil, the better the flavour. ”
Trim, halve and chop the leek into chunks, and peel the garlic.
Put a large pan of salted water on to boil, then drop in the leek and garlic cloves. Cook for 3 minutes, then add your cavolo nero, kale or cabbage. Cook for another 3 to 3½ minutes, but no more! Don’t be tempted.
Using tongs or a slotted spoon, move the veg to a liquidiser – it’s OK if a bit of water comes with it. Add your oil and liquidise until you’ve got a vivid green purée, the same consistency as double cream. If it’s a bit too dry, add a splash of the cooking water. Have a taste, season with sea salt and black pepper, then put aside.
Bring the water back to boil, and cook the pasta according to the packet instructions.
Drain and return the pasta to the pan, add the sauce and allow it to simmer over a medium-low heat for 30 seconds.
As it comes back to the boil, remove from the heat and finely grate in the Parmesan. Be quick, so your pasta doesn’t overcook, then check the balance of cheese, salt and pepper.
Finely grate over extra Parmesan, then serve on a big platter and eat as soon as possible.