Host and Lord John Grey star Berry joked how Gabaldon and Heughan were the “real power couple” of Outlander rather than Jamie and Claire Fraser (played by Caitriona Balfe).
Reflecting on their relationship, Gabaldon said: “It got off on the right foot.
“I knew absolutely nothing about making a movie and I was completely surprised because he had done a wonderful job with the audition.
“He was using books, lines straight out of the novel – no adaptation for script or anything like that. So it was my lines. You know Sam, that’s how [Jamie] would say that.
“It’s amazing. I was thrilled by this, so I was looking for Sam online and he was.”
The pair are said to have a close working relationship with Heughan consulting Gabaldon about the character of Jamie to ensure his portrayal was as close to the source material as possible and doing justice to Jamie.
Gabaldon said Heughan also had “his own sense” of Jamie, which she said was “pretty close to mine”, suggesting the pair were on the same page when it came to characterisation.
Outlander seasons 1 to 5 are streaming on Amazon Prime Video now