Soften the onion and garlic

• Heat the olive oil and half the butter in a large frying pan over a medium heat.
• Add the onion and cook until soft and translucent.
• Stir in the garlic and chilli flakes and cook until fragrant.

Cook the squash

• Add the cubed butternut squash and stir to coat.
• Pour in the vegetable stock and season with salt and pepper.
• Cover and simmer until the squash is completely tender.

Boil the pasta

• Bring a large pot of salted water to the boil.
• Cook the pasta until al dente, then drain, reserving a little pasta water.

Blend the sauce

• Blend the squash mixture until completely smooth.
• Return to the pan and stir in the cream, remaining butter and most of the parmesan.
• Loosen with a splash of pasta water if needed.

Combine and serve

• Toss the drained pasta through the sauce until well coated.
• Serve topped with the remaining parmesan and a grind of black pepper.