For the pumpkin stock, add all of the stock ingredients to a saucepan and bring to the boil. Reduce the heat and simmer for one hour. Remove the pan from the heat, set aside to rest for 20 minutes, then strain the stock through a sieve.
For the soup, preheat the oven to 180C/350F/Gas 4.
Cut the top off the acorn squash. Scoop out the seeds and fibres from the middle and discard.
Rub the squash inside and out with a little olive oil and season the insides with salt and freshly ground black pepper. Drizzle the remaining olive oil over the squash lids.
Place the squash and their lids into a roasting tray and roast for 40-45 minutes, or until tender.
Meanwhile, chop half of the pumpkin wedges into cubes and set aside.
Heat the vegetable oil in a large heavy-based saucepan over a medium heat. Add the onion, one teaspoon of the cinnamon and a pinch of salt, then fry gently until the onion is very soft.
Add the cubes of pumpkin and continue to cook until tender. Add enough pumpkin stock to cover the pan ingredients and bring the mixture to the boil. Reduce the heat and simmer for 20 minutes.
Meanwhile, heat the butter in a large ovenproof frying pan until foaming. Add the pumpkin wedges and season, to taste, with salt and freshly ground black pepper. Fry for 2-3 minutes on each side, or until golden-brown on both sides. Sprinkle with the remaining ground cinnamon and the caraway seeds. Continue to cook for a further five minutes, then add the honey and transfer to the oven for 6-8 minutes, or until dark golden-brown and tender.
Add the roasted pumpkin to the pot of simmering pumpkin and mix together well, adding more stock if necessary.
Continue to simmer for a further 5-10 minutes, or until all of the pumpkin is tender. Stir in the cream and season, to taste, with salt and freshly ground black pepper.
Remove the pan from the heat and set aside to cool for 10 minutes. When the soup has cooled slightly, blend it in a food processor until smooth.
Meanwhile, for the pumpkin seeds, heat the oil in a frying pan over a medium heat and add the cleaned pumpkin seeds and cinnamon. Fry the seeds for 1-2 minutes, or until just toasted.
To serve, place one cooked acorn squash onto each of four serving plates. Ladle in the pumpkin soup, then top with a slice of crispy pancetta (if using), a dollop of crème fraîche, the toasted pumpkin seeds and a sprinkling of chives. Cover the squash with the lid and serve.