Pre-heat oven to moderate (180 degrees celsius, fan-forced).
Beat eggs yolks and sugar on med-high speed until creamy (and a pale colour).
Add melted butter, milk, lemon juice and lemon rind and mix on low speed until combined.
Gradually add flour while mixing on low speed. Set aside the lemon mixture.
In a separate bowl, beat egg whites until soft peaks form.
Add sugar slowly while continuing to beat until sugar has dissolved to form a meringue mixture.
Gently fold the meringue mixture into the lemon mixture until combined.
Pour mixture into well-greased large baking dish or evenly into 6 well-greased ramekins.
Place the baking dish or ramekins into a larger baking dish and fill the larger baking dish with boiling water so it comes half way up the sides of your smaller baking dish or ramekins.
Place in oven and bake uncovered for 30 minutes (if individual ramekins) or 50 minutes (if large baking dish) or until golden on top and just a little wobbly.
Serve warm, dusted with icing sugar and with cream, ice cream or custard.