In their latest film, Le Week-End, the pair play a married couple in their late fifties who have decided to spend the weekend of their 30th wedding anniversary in Paris.
From the start, it's clear that Meg (Duncan) feels unfulfilled and finds her husband Nick (Broadbent) irritating, despite a few tender moments of affection.
"She's just a little bit angry," says Duncan, 62. "She's wanting more and is wondering how much time is left. She still feels like a woman with appetites and she wants her husband to keep up."
Though Meg is only human, a free-spirited but frustrated woman who knows her own mind, she's also quite a hard character to like.
Duncan agrees. "I do stand by her, though," she says. "I think she's real, and I'm very lucky to play such a complex woman who I completely believe in."
While the subject matter might not be particularly joyful, the movie is charming, touching and sharp (as well as funny, particularly the scenes with Jeff Goldblum, who plays an egotistical American writer).
Filming in Paris was a delight, says Duncan.
"We were seeing the city every working day – we were on the streets and shooting in restaurants, so we could never forget where we were. It was heaven," she smiles.
It wasn't her first visit to the city of love, of course. One year, she spent Christmas there with her husband, the Scottish stage actor Hilton McRae, and says it was one of her best Christmases ever.
"We had been together for a few years and we sort of ran away from family responsibilities and stayed in someone's garret in Paris," she explains.
It sounds like Duncan has a bit of Meg's free-spirited, fun-seeking side? "Well, I don't think I'm very sensible," she admits, laughing.
This is the second time Duncan has played Broadbent's wife. The first was in the TV film Longford, in which Broadbent played Labour peer Lord Longford, who spent years campaigning for the parole of Moors murderer Myra Hindley. Duncan played Lady Longford.
In Le Week-End, the pair look very at ease with each other. So much so that I wonder if they were sent off together for a day of bonding. Duncan laughs hysterically at the suggestion.
Hull and East Riding DM
Comments to taglines82@gmail.com