Pumpkin Pasta

Put a large pan of water on to boil for the pasta, then keep it covered at a simmer until needed. Meanwhile, peel the pumpkin, scoop out the seeds and stringy fibres, and cut the flesh into 2 cm cubes; there should be about 750 g.

Finely chop the onion and thinly slice the garlic. Strip the leaves from the rosemary sprig and chop them finely, and finely grate the Parmesan.

Warm 4 tbsp of the olive oil in a large, deep frying pan or sauté pan (about 28 cm) over medium-low heat. Add the onion with a pinch of salt and cook for 8 minutes, stirring now and then, until soft and translucent but not browned. Stir in the garlic, the chopped rosemary and the chilli flakes, and cook for 1 minute until fragrant.

Add the pumpkin, turn it in the oil and cook over medium heat for 5 minutes, stirring now and then, until the edges start to soften.

Salt the hot pasta water generously and ladle about 200 ml of it over the pumpkin. Cover and cook gently for 15 to 20 minutes, stirring from time to time, until the cubes are soft enough to crush against the side of the pan with a spoon. Add a splash more of the pasta water if the pan runs dry.

Uncover and crush about half the pumpkin with a potato masher or a fork, leaving the rest in soft pieces that will catch inside the pasta. If the sauce looks watery, let it bubble uncovered for 2 to 3 minutes; it should be thick and rough, like a loose mash. Season with salt and black pepper and set the pan aside off the heat.

Bring the pasta water back to a rolling boil and cook the rigatoni for 2 minutes less than the packet says, stirring now and then. Scoop out a mugful (about 250 ml) of the cooking water before draining.

Drain the rigatoni and tip it into the pan with the pumpkin over medium heat, with a splash of the cooking water. Toss for 2 minutes, adding more of the cooking water a little at a time, until the pasta is al dente and coated in a creamy sauce.

Take the pan off the heat and stir in two thirds of the Parmesan, loosening with a little more cooking water if needed, until the sauce is glossy and clings to the pasta. Serve in warm bowls, topped with the rest of the Parmesan and a thread of the remaining olive oil.