Combine butter and sifted icing sugar in
bowl, stir enough juice to make smooth and spread able.
Beat butter, rind, sugar and egg yolk in
small bowl until light and fluffy. Stir in sifted flour and enough
juice to make ingredients cling together. Turn dough onto lightly
floured surface. Knead gently until smooth. Roll 2 level teaspoons of
mixture into a ball, place onto greased oven tray and flatten
slightly. Repeat with remaining mixture, allowing about 4 cm between
cookies. Bake in moderate oven for about 20 minutes or until lightly
browned. Cool on wire rack. Spread cold cookies with icing.