Beat egg-white until soft peaks form, gradually add sugar, beat until dissolved. Fold in finely chopped walnuts, sifted cornflour and rum. Drop half-teaspoonfuls of mixture on to well greased lightly-floured oven trays. Allow room for spreading. Bake in slow oven 30 mins. When cold, sandwich together with chocolate cream.

Chocolate Cream: Melt thoroughly chopped chocolate in basin over hot water. Cool a little. Cream butter and sugar until light and fluffy. Stir in rum and chocolate. Refrigerate until ready to use.