He's the king of 'documentary style comedy' (don't call it 'mockumentary' - he says he's not mocking anyone) and now Christopher Guest is back with his new TV series Family Tree starring Chris O'Dowd as a down-and-out guy trying to find his roots through genealogy.
But Guest didn't do it alone as British actor and filmmaker Jim Piddock co-created the funnyman's version of Who Do You Think You Are? as it follows the journey down familial history's lane for the lonely Tom Chadwick.
'He has no girlfriend, no job, and no real close ties to his family. So, as all of us do at some point in our lives, he wants to find out who he is, what his place in the world is, and where he fits in the larger picture of the chain of history,' Jim describes his lead protagonist.
'The specifics of what he finds may be funny or unusual or even mundane, but the show is as much about why he's doing it, what happens and who he meets along the way as it is about what he discovers.
'The truth is very few of us are related to Napoleon or Cleopatra. Although, those are bad examples as I am actually descended from both of them.'
The project started two years ago when over a lunch, Guest told Piddock about the research he'd conducted which concerned his own history.
'He told me he'd been delving a bit into his own family tree, and did I think the whole genealogy arena is something that might work as a comedy? By the end of the lunch, we both decided that if it was viable, it would be far better as a TV series than a film.
'There's no traditional three act structure - or beginning, middle and end - to a family tree,' Jim explains. 'By its nature it has almost infinite different branches, or episodes, to explore in every direction.'
For those fans of Best In Show, For Your Consideration and other classic Guest films you'll be happy to find a wealth of his regular players popping up in the series.
'It was always the intention to use as many of Christopher's regular cast members as we could,' Jim says. 'Some we had in mind for specific roles very early on, some came up as we were writing, and some fit into the puzzle once we'd finished writing.
'Nina Conti and Monkey had done a scene in For Your Consideration, so they were more of a known quantity.'
But after making his name on the small screen in The IT Crowd, and getting greater popularity through his role in Bridesmaids and another little HBO show called Girls, Chris O'Dowd was on the team's radar and 'at the top of [their] list early on.'
The documentary style comedy is welcome territory for the writing duo, and Jim's description of Christopher as a 'pioneer in the field' is more than apt, for without This Is Spinal Tap or Waiting For Guffman, we wouldn't have had The Office, Parks & Recreation or many other shows currently dominating the TV schedules. But why has the style been so successful on the small screen?
'I think it started to become more of a common language in television comedy,' Jim muses. 'We were very much aware of that fact and actually tried to use a new documentary technique which we called the walk-and-talk interviews, in addition to the more familiar talking head ones.
'The other thing that's different from The Office, either the US or UK versions, and shows like Modern Family is that our characters never address the camera directly, or show any awareness that they're being filmed. This creates a more fly-on-the-wall feel.'
But it's not as though the writing team are checking out the competition for Jim admits he doesn't 'watch that many comedies on TV and Chris watches none.'
'That helped us create a show that wasn't really like anything else on TV,' Piddock says. 'I find most stuff quite mean-spirited or obvious today.'
That being said, the writer has 'enjoyed Modern Family whenever [he's] watched it', however, most of his favourite shows like Reno 911, Sex And The City, Alan Partridge and Brass Eye aren't on the air anymore.
But Jim hasn't just co-written the eight episode series, but will also star in Family Tree, as Mr Pfister, whose South African accent was chosen because of a dare from Guest: 'When we conceived that part, early on in the writing process, Chris asked what voice or accent I was going to use and jokingly, I said South African because it was the least funny accent I could think of.'
'I mean, there's the apartheid connotations, and it's usually used by villains in action movies, and I couldn't think of a single film or TV comedy where anyone had ever used that accent,' Jim remembered. 'So he dared me and, whenever Mr. Pfister came up in the writing process, I started riffing as the character with a heavy South African accent and it always made him laugh.'
So what about Jim's own family tree? The 57-year old hails from Rochester in Kent, and says that if he had more time he probably would investigate his genealogy.
'My brother's done quite a lot, and bizarrely, a few months ago he was left a box of old photos and memorabilia by an aunt we never knew, 'Jim tells me. 'There are a few things and some very good stories that I do know already, and a direct connection between my grandfather and Charlie Chaplin - but that's a whole other interview.'
Family Tree premieres on BBC 2, tonight, at 10pm.