For the Red-wine Caramel Sauce with Hazelnuts

• 200 ml (7 fl oz) red wine, preferably burgundy
• 1 tablespoon red-wine vinegar

Bring the wine and vinegar together to the boil and then boil rapidly until it has reduced by half. Set aside. Gently melt the sugar in a separate pan over a medium heat until it has turned into a golden caramel. Add the butter and the scraped vanilla pod or essence and cook for a further 2 minutes. Add the reduced wine mixture, remove from the heat and add the chopped hazelnuts. Leave the sauc