How to hang THAT mirror from The Range

How to hang THAT mirror from The Range

I think what the title of this post should be is 'how to hang THAT mirror from The Range (you know, that ginormous ridiculously heavy one?!) when you have crappy plasterboard walls' but that seemed too long to be reasonable!

I'm sure any interior junkie will know exactly what mirror I am talking about, but, in case you don't follow every interiors account worth following on Instagram, then basically I am referring to a large arched window mirror from The Range home shop made from ivory painted metal...