Lisa Kudrow was a dream cast member for the writers of Channel 4's comedy drama Feel Good, but they admitted to only sending her the scripts "as a joke."
The new series tells the story of comedian Mae Martin, as she enters into an intense new relationship while coping with the struggles of being a recovering addict.
Friends star Kudrow plays Mae's mother, who attempts to control her life remotely from Canada through hilariously awkward interactions on Skype.
Martin, who co-wrote the show and plays a version of herself, said: "She was a fantasy casting that we wrote, but it was just a daydream and then we sort of sent them to her as a joke."
She and her writing partner Joe Hampson had been big admirers of Kudrow's work on Friends, as well as more recent projects like HBO's The Comeback which saw Kudrow take on the role of fading sitcom star Valerie Cherish, who desperately attempts to revive her career by filming a reality show.
"When she flew over to the UK, we were in the room reading with her and it was just so thrilling. Being on screen with her was very surreal and very wonderful," Martin told RadioTimes.com.
She added: "Lisa and Sophie Thompson and Charlotte [Ritchie] all have this ability to be so poignant and then so funny. That sudden emotional gut-punch out of nowhere, but then to be experts at comic timing as well – it’s a very rare skill."
Kudrow's filming for the show took her to Blackpool, where she developed a taste for a classic British snack.
Martin recalled: "Our craft services table was like digestive biscuits and she’s used to an organic one where they’ll make you an omelette in two seconds. But she was so nice, and she was like 'I love these biscuits' and she now orders them to LA.
"She sent me a photograph, she has like 12 tubes in her cupboard. She has them with tea in the morning."
Working with Kudrow was particularly surreal for Martin, who was such a big fan of Friends growing up that she once wrote a fantasy episode herself - but it had one major problem.
"There was a part for me in it where I start a band with Phoebe, I was Rachel’s little sister and in the script I’m Joey’s love interest, but I was 12!
"It didn’t occur to me that it was wrong and Joey’s like 'How you doin'?' And they’re all like 'Joey!' But I was 12! Gross."
A Friends reunion special is set to land in May, bringing the original cast and creators together for a celebration of the beloved sitcom.
Feel Good airs on Channel 4 at 10pm on Wednesday, 18th March and will be available to stream as a box set on All 4