Flan case
8oz digestive biscuits 
2oz butter 
1tbs castor sugar
Filling
2 large lemons
14 pint double cream
6oz can condensed milk

Crush biscuits and mix with melted butter and sugar. Put mixture into 7inch flan dish and bake at 150c for 8mins. Leave to cool. 
Squeeze juice and grate zest from lemons. Mix with cream and condensed milk. Pour into flan case and chill until firm.