Roll out the pastry to a 50 x 30 cm/20 x
12 in rectangle, trim the edges, then cut lengthways into 2.5 cm/1 in
strips. Mix the egg yolk with the milk and brush the pastry carefully
with the mixture, making sure that no egg gets on to the underside of
the pastry or it will stick to the moulds. Twist each strip in a
spiral round a metal horn mould, overlapping the edges of the pastry
Brush again with egg yolk and milk and
place on a baking (cookie) sheet with the end underneath. Bake in a
preheated oven at 200°C/400°F/gas mark 6 for 15 minutes until golden.
Leave to cool for 3 minutes, then remove the moulds from the pastry
while it is still warm. Leave to cool. Whip the cream with the icing
sugar until stiff, then pipe into the cream horns. Dust with a little
more icing sugar.