Combine the butter, fruit, sugar, lemon and orange rind and juice, Guinness and brandy in a saucepan. Bring to the boil over medium heat, cover and simmer for 10 minutes. Set aside to cool slightly. Add the nutmeg, cinnamon, allspice, ginger and cardamom to the mixture and transfer to a large bowl. Cover with plastic wrap and soak for 3 days in a cool place, stirring dai