To decorate - whipped cream, marrons glace
Peel the chestnuts removing all traces of
the brown skin. Put the chestnuts in a medium saucepan with the milk,
half the sugar and the orange rind. Heat until simmering, then cook
gently for 20 minutes or until the chestnuts are very soft. Lightly
butter a 15cm (6 inch) cake tin.
Place the remaining sugar in a small
saucepan. Stir in 45ml (3 tbsp) water and heat gently until the sugar
has dissolved, then boil rapidly until the syrup turns to a pale golden
brown. Remove the pan from the heat and immediately pour the caramel
into the base of the prepared tin. Leave to cool.
Puree the chestnuts with half the milk in
a blender or food processor. Add the orange juice and rum or brandy, if
using. Whisk the egg whites until they form soft peaks, then fold them
into the chestnut puree. Pour hot water to a depth of 2.5cm (1 inch)
into a large round gratin dish. Spoon the mixture into the cake tin and
stand it in the gratin dish. Bake the chestnut mould at 160C (325F) mark
3 for 35-40 minutes or until set. Leave to cool, then chill for several
hours or overnight. Turn the mould out of the tin on to a plate just
before serving. Decorate.