Our latest guest is another of those 'annoying' multi-talented sorts, who's written, directed and produced a whole host of movies to widespread acclaim.

Sacha Gervasi's first film was The Big Tease, which he co-wrote with Craig Ferguson. He went on to pen The Terminal, made into a film directed by Steven Spielberg and starring Tom Hanks. That's some feat.

He also directed the brilliant rockumentary Anvil, which tells the deeply personal story of a heavy metal band who've been plugging away for 30 years.

And it's with Anvil that we began. If you're unfamiliar with their work, it's pure Spinal Tap, only real …