Peel the butternut squash and reserve the long strips of skin.
Discard the butternut squash pulp and chop the remaining butternut squash into chunks.
Heat the olive oil in a large casserole, add the onion and butternut squash and plenty of butter (to taste) and cook untill brown and caramelised.
Pour over the stock. Simmer for 20 minutes. Remove from the heat, leave to cool slightly and then blend using a food processor or hand-blender to the desired consistency.
Add hot smoked paprika and season to taste with salt and freshly ground black pepper.
For the crisps, preheat the oven to 140C/275F/ Gas 1.
Place the reserved butternut peelings in a roasting tray and top with the olive oil, sherry vinegar, chopped rosemary and put in the oven to cook for 20 minutes on a low heat to crisp up.
Remove the crisps from the oven and place on kitchen paper to absorb any excess oil.
Serve the soup with the skin crisps.