Pre-heat oven to 200C.
Put the saffron threads onto a non-stick tray and in the oven to roast for no more than 5 minutes.
In a pot or microwave,heat the milk so that it is lukewarm. Crush the saffron threads between your fingers and sprinkle into a cup. Add 2 tablespoons of the warm milk and set aside to infuse.
Crumble the fresh yeast into a small bowl,add a pinch of sugar and the warm milk. Whisk with a fork until combined. Cover and place in a warm,draught-free place for 20 minutes or until a light froth has formed on top. Sift flour and salt into a large bowl. Add the sugar and spices and rub in the finely chopped butter until it resembles course crumbs. Make a well and pour in the yeast and saffron liquid.
Knead gently until smooth and forming a ball.
Place the dough in a lightly oiled bowl,cover and allow to rise again in a warm place for 1½ to 2 hours - or until the dough has almost doubled in size.
Add the currants to the dough and knead together on a floured surface until combined. Shape into a loaf and put into a well-greased loaf tin. Cover and rise again for half an hour before baking for about 35 minutes or until golden brown on top (check it at 30 minutes).
Mix together 2 tablespoons of milk and 2 tablespoons castor sugar and while loaf is still warm,brush with mixture.
Leave to cool a little before turning out.