Cream the yeast with the water.
Sift the flour and salt into a large bowl.
Stir in the sugar and make a well in the centre.
Pour in the milk, butter, egg yolks and the yeast liquid.
With one hand or a spatula, draw the flour into the liquid and beat until the dough comes away from the sides of the bowl.
Turn onto a lightly floured surface and knead thoroughly for 8-10 minutes until smooth and elastic.
Place in a clean bowl, cover with a damp cloth and leave to rise in a warm place for 1 1/2 hours or until doubled in size.
Meanwhile make the filling.
Whisk the egg whites until they form soft peaks.
Fold in the sugar, a little at a time, using a metal spoon, then beat until smooth and glossy.
Fold in the nuts, orange rind, lemon rind and nutmeg.
Turn the dough onto a floured surface and knead for 5 minutes.
Cut the dough into 2 pieces and roll each to a large rectangle.
Spread with the filling.
Roll up each piece of dough as for a Swiss (jelly) roll.
Place on separate greased baking sheets and form each roll into a circle, dampening the edges and pressing them together to seal.
Place in oiled polythene (plastic) bags and leave in a warm place for 45 minutes or until doubled in size.
Remove from the bag.
Bake in a hot oven, 425°F, Gas Mark 7 for 15 minutes.
Reduce the temperature to moderate, 350°F, Gas Mark 4 and continue to bake for 40 minutes.
Turn onto a wire rack and cool for 15 minutes.
Brush with honey.
Decorate with walnut halves and crystallized (candied) fruit slices.