A few short clips from the interview Graham Norton did to Ian McKellen after the documentary Ian McKellen Playing the Part, to which Martin was invited have been published.
Here’s a gif from one of the short clips, we’ve uploaded them in case they get deleted but you have the original source next to the title of each.
Short clip #1 (source)
Short clip #2 (source)
Short clip #3 (source)
Short clip #4 (source)