The night before, put the prunes in a saucepan, cover with water and add the tea bags. Boil for 5 minutes, then take the pan off the heat, cover and leave overnight. The next day, drain the prunes and stone them.
Prepare the pastry cream: bring the milk to the boil. Beat the sugar with the egg yolk until pale, then mix in the flour. The mixture should be like very fine breadcrumbs. Grad