The answer, I finally tell him, is Al Murray.
“Oh, you’re joking!” he cries. “Really?”
The irony being that Shaun – still best known as Barry from EastEnders, despite being killed off 15 years ago – is about to become a regular on Al’s Great British Pub Quiz, launching tonight on Quest.
He’s going to be its know-it-all barman. Or know-nearly-all.
To be fair, he does have an impressive track record, quizzing-wise, having been “lucky enough” as he modestly puts it, to triumph on Celebrity Mastermind, Pointless, Eggheads and The Chase.
So, despite having left school with barely a qualification to his name, he’s clearly a bit of a brainbox.
“Well, I think the questions are slightly easier on the celebrity shows,” he insists.
Shaun’s final moments as Walford’s loveable loser Barry Evans, in January 2004, saw him take a fatal tumble from a cliff edge, albeit with a little help from his less than wholly loving wife Janine.
So did that hurt, I ask?
His reply – “It hurt my bank manager” – clearly isn’t entirely a joke.
EastEnders had been his very first job after stage school (he’d previously been a postman, joined the navy, worked for Club 18-30, then stacked shelves in Safeways) and it served him well for 10 years.
“It was nerve-wracking at first, acting with the likes of Barbara Windsor or Wendy Richard, the most famous people in the country. But you soon get used to it.”
After EastEnders, the work offers didn’t exactly flood in.
This was a worry.
Soap fame may have had its drawbacks (“After Barry set fire to the car lot, someone threw a stone at my window and shouted, ‘Arsonist!’”) but not as many as being overdrawn.
Landing a role on Ricky Gervais’s Extras was something of a godsend, then, but it did mean poking fun at his own career. Was that a wise move in such a cut-throat industry?
“I know what you mean, Mike, but when they sent the scripts I thought, ‘This is good.’
“And I really didn’t mind. People like Kate Winslet and Ben Affleck were doing it. Then for the second series, I was in scenes with Bowie and Robert De Niro.
“Even now, I’m still getting work off the back of Extras. It’s the gift that keeps on giving!”
And does he look back so fondly on his time in 2017’s Celebrity Big Brother?
“Well, I needed the money,” he admits.
“It’s not a great thing for an actor to be seen in, I don’t mind saying that. But however successful you’ve been in the past, it doesn’t matter a damn to a mortgage broker if you can’t prove what you’ll be earning next year.
“My wife Adele and I had found ourselves renting for a few years, throwing money down the toilet. At my age, that’s no good. So Big Brother, in fairness, got me the down-payment on a house. I couldn’t have done that without it.”
As for the future, Shaun has a role in an upcoming BBC One sitcom, Mister Winner.
He also keeps busy with stand-up comedy, singing gigs and after-dinner speaking. “And if a really brilliant acting job comes up, I’ll just cancel the stand-up, even if I have to upset someone.”
Shaun acknowledges that his two biggest parts, playing Barry for ten years, then poking fun at that on Extras, have had their downside.
“It’s cost me a credible career in drama. I realise that, I’m not stupid.”
But he remains optimistic. I suggest perhaps he’d love a role in Corrie or Emmerdale.
“I would,” he says. “They’re excellent, they do comedy very well.
“I wouldn’t mind another ten years in a soap. I think I’d be a bit more grateful this time around.”
• Al Murray’s Great British Pub Quiz starts tonight at 10pm on Quest (Freeview 37/114, Freesat 167, Sky 144 , Virgin 172/217).