Surface 's Reese Witherspoon on 'Sublime' Reunion with Morning Show Costar Gugu Mbatha-Raw

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Reese Witherspoon and Gugu Mbatha-Raw are a TV show's match made in heaven!

At the premiere of their new AppleTV+ show Surface, the costars chatted with PEOPLE about why it's "a treat" to work together for the third time after previously both appearing in The Morning Show and A Wrinkle in Time.

Witherspoon, 46, who is one of the executive producers of the show, said working with Mbatha-Raw is "the greatest."

"She's just sublime as a performer," the 2022 Emmy nominee told PEOPLE.

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The Hello Sunshine founder continued that the Belle star, 39, is "light and beautiful and you can't take your eyes off her." Added Witherspoon, "This show and this character, I think is one of my favorite characters she's ever played, because there's a lightness and a darkness to it."

In Surface, Mbatha-Raw plays Sophie, a woman who is desperately trying to rebuild her life after a suicide attempt while piecing together the things that led up to that moment.

As for the choice of casting Mbatha-Raw, Witherspoon attributed a lot of it to her work in The Morning Show, where she played head booker Hannah Shoenfeld. "We saw the reaction to her character on Morning Show, it was just so profound and audiences loved her," Witherspoon said. "We wanted to do more and we want to partner with her as a producer because she brings so much to the work, is so professional, she's got great ideas, works so hard with the directors and the crew to make it happen and it's just been a it's been a joy."

"I love to see her soar," the Wild star said, "I get emotional."

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Mbatha-Raw was just as complimentary of her costar and fellow executive producer, telling PEOPLE it was "such a treat" to work with Witherspoon again.

"I feel so excited because it was my first opportunity to be an executive producer on the project," the Loki star said, noting that it is an "incredible growth opportunity."

For her part, Witherspoon said Mbatha-Raw "works her tail off and she really cares and she puts in the hard hours. A lot of people don't know what we do all day, 15, 16, 17-hour days and she's one of the really, really hard workers in our business so it's thrilling to watch her story like this."

Mbatha-Raw noted, "I'm so thankful for Hello Sunshine already willing to work in terms of empowering women and opening the door for other women behind them to really feel like they can grow the industry and look on the production not just in front of your house," the actress said.

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When asked what it's like to actually work with Witherspoon, Mbatha-Raw said, "Oh my gosh. I mean, everybody feels like they know Reese."

She continued, "You know, I know Reese in a professional capacity but she's so encouraging. So positive, incredibly smart. Obviously, an incredibly shrewd businessman, has great taste, and she's just always been really encouraging and, you know, just to lead by example."

Mbatha-Raw added that Witherspoon is "a great boss and a great executive and a great mentor."

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Surface debuts Friday on AppleTV+.