Sift
together flour and chocolate powder and add
margarine or butte, cut into pieces. Cut in until
mixture resembles fine breadcrumbs. Mix to a firm
dough with water.
Knead dough lightly and roll out to fit an 8 inch
(20cm) fluted pie plate or quiche pan. Bake blind
(lined with foil weighted with dried beans) for 20
minutes.
To
make filling : Place 1/4 cup (60ml) sugar in a bowl
with 1 egg and 1 egg yolk. Beat well and mix in
flour. Warm milk with vanilla extract and pour onto
egg mixture, stirring. Return to milk pan and stir
over gentle heat until thickened. cool slightly.
Pour into flan shell. Let cool then chill.
Beat
remaining egg white until stiff and peaking, then
whisk in remaining sugar. Whip cream with rum and
fold gently into egg white. Spread mixture over
custard filling and sprinkle with nutmeg.