Suggestions for Layout

This should be a quick question. I am trying to create a layout on my Xamarin.Forms page that looks like this:

|--- Label w/ Fixed Width ---| |--- Entry Box w/ Remainder Width ---|

So if the screen is wider, then it would look like this:

|--- Label w/ Fixed Width ---| |----------------------- Entry Box w/ Remainder Width -----------------------|

So the label will have a fixed width on the screen, but the entry field will take up the remainder of the width on that one line.

2 Questions:

1) Would a StackedLayout or RelativeLayout work better for this?
2) Does anyone have example code (not XAML) on doing this within one of the above layouts?

Thanks!