Heat the oil in a large saucepan, add the onion and cook over a medium heat, for 3-4 minutes, until softened, stirring occasionally. Stir in the potatoes and pumpkin or butternut squash, cover and cook for 5 minutes.
Stir in the spices, cook for 1 minute then pour over the stock. Cover and simmer for 35-40 minutes until the potatoes and squash are tender. Transfer to a food processor or liquidiser and blend in batches until smooth. Return to the pan, stir in the cream, if using, and reheat gently. Season to taste.
Dry fry the bacon in a large frying pan until crispy, then drain on kitchen paper, then roughly chop. Serve the soup topped with the
crispy bacon, with the crumbled Cropwell Bishop Stilton and garnished with a sprinkling of chives.