Stir the yeast into the lukewarm water with 1/2 teaspoon of the sugar until it is well blended; leave for 5-10 minutes until frothy.
Bring the milk to the boil, add the butter or margarine, the remaining sugar and the salt; stir until dissolved, then leave to cool until lukewarm.
Measure about 1 1/2 cups of the flour into a large bowl and mix in the beaten eggs with the yeast liquid and milk mixture; beat well so that the mixture is smooth, then work in the remaining flour to give a fairly soft dough.
Turn the dough out onto a lightly floured surface and knead well until smooth and satiny.
Shape the dough into a ball and place in an oiled plastic bag.
Leave in a warm place until it has doubled in size.
Turn the risen dough out onto a lightly floured surface, punch down and knead well for a few minutes; then knead in 4 tablespoons of the candy crystals.
Shape the dough into a rectangle.
Return the dough to the plastic bag and leave overnight in a refrigerator or cold place.
The next morning bring the dough out and let it warm to room temperature.
Cut off a piece of the dough the size of an egg.
Form the remaining dough into a ball and put it in a greased 5-cup brioche or bundt pan.
Cut a small cross in the top of the dough and form the remaining small piece of dough into a pear shape.
Then insert the point of the pear into the middle of the cross.
Leave the dough to rise again in a warm place for about 2 hours or until it has reached the top of the pan.
Brush the risen dough with an egg wash made by lightly mixing together the egg yolk with 1 teaspoon of water, then sprinkle with the remaining 2 tablespoons candy crystals.
Bake in the center of a moderately hot oven (375°F) for about 40 minutes.
If the bread looks as if the top might overbrown during cooking, cover it with a small piece of foil.
When the bottom of the brioche is tapped and it sounds hollow it is ready.
Turn it out onto a cake rack and leave to cool.
The brioche is best if eaten the day it is made.