Put the butter in the milk and heat to hand warm. Pour into the bowl of a food mixer with a dough hook attached. Switch on at low speed and pour in the flour, yeast, sugar and salt. Work for 5 minutes, then add the sultanas, currants and candied peel, and continue to work for a further 5 minutes.
Remove to a floured surface and shape into a ball, then transfer to a large oiled bowl. Cli