Whisk together the eggs and caster sugar.
Squeeze and zest three whole lemons.
Combine and whisk together over low heat.
Remove from heat and add cold butter cubes.
Beat egg yolks with sugar until pale, then add in milk, oil and flour.
Beat egg whites until soft peaks form, then add sugar.
Beat until stiff peaks form.
Fold the meringue into the batter.
Pour into muffin cups and bake at 170 degrees celsius for 20 minutes or until golden brown.
Let cool and pipe in the lemon curd.
Garnish with berries or icing sugar and chill before serving.