How to create a custom view and renderer which can display children

I have another thread; but think it might be badly worded, so I want to simplify my question.

how can I write an iOS renderer to allow me to do this:

<controls:MyAwesomeControl>
    <controls:MyAwesomeControl.FooterView>
        <StackLayout BackgroundColor="Fuchsia">
            <Label Text="test" />
        </StackLayout>
    </controls:MyAwesomeControl.FooterView>
<controls:MyAwesomeControl>

i.e how do I get the FooterView contents, and turn them into iOS views, and have them render correctly for layouts and their children.