Preheat the oven to 180C/350F/Gas 4.
Heat one tablespoon of the oil in a frying pan over a medium heat and fry the onion for 4-5 minutes, or until softened. Add the sherry and cook for a further 1-2 minutes, or until the volume of the liquid has reduced slightly.
Add the garlic, paprika, chilli, tomatoes and the remaining oil and cook for a further 18-20 minutes, or until the sauce is thick and the tomatoes have softened.
Stir in the prawns and spoon into an ovenproof dish. Sprinkle over the breadcrumbs and bake for 15-17 minutes, or until golden-brown on top.
Serve immediately with the crusty bread.
