Mix together the flours, sugar, and salt. Rub in the butter until the mixture is like fine breadcrumbs. Lightly beat the egg and mix with the top of milk. Make a well in the center of the flour mixture and pour in the egg and cream. Knead with the hand till a soft pastry is formed. Sprinkle pastry board with a little rice flour and roll pastry out thinly. Prick with a fork and cut into rounds or fingers. Place on greased paper a little apart and bake in a moderate oven till golden brown. Cool on a wire tray.