Serves 8 to 10
Carefully cut a lid out of the pumpkin and keep it. Remove the seeds and fibres from the middle and discard them. Carefully hollow out all the flesh with a knife and a spoon. It is absolutely imperative that you do not cut right up to the inside of the skin or pierce it as it will no longer be usable as a tureen. You want to scrape and cut into the pumpkin up to no more than half an inch to the inside. When all the flesh has been removed put it to one side chop up the onions nice and fine. Melt the butter in a large pan and throw in the onions cooking them slowly until they are soft. Add the pumpkin and all the remaining ingredients except the stock and sherry. Put the heat to medium and the lid on the pot occasionally stirring the contents from time to time, to avoid it catching, until the pumpkin is totally cooked through. Add the stock and then either blitz the mixture with a blending stick or in a food processor. Bring the mixture to a low simmer and cook for a further half an hour. An hour before eating the pumpkin pour the soup back into the shell and stir in the sherry put on the lid and bring the pumpkin up to heat at 170.Lift the whole pumpkin on to a suitable tray and carry it to the table, with a ladle.