What is “Kate Winslet” as a director? (Exclusive)

Kate Winslet sat in the director’s chair for the first time this year with the production of Goodbye June, and the film’s stars have a lot to say about the film.

At a special screening of the Netflix film in New York City, Toni Collette and Timothy Spall opened up to PEOPLE about what it was like not only to be next to them, but also behind the camera with the Oscar-winning actress who directed, produced, and starred in the film.

Collette, who Winslet named as an actor she would like to work with in 2016, called it a “dream come true.”

“I’ve been saying that for years, too,” Colette, 53, said of working with Winslet. And joining forces for the stars’ directorial debut, a family affair based on a screenplay written by Winslet’s son Joe Anders, was especially special.

“I mean, it was more than I expected because I thought we were just going to have our act together,” Colette continued. “But when someone chooses you to be a part of their directorial debut, it’s a big deal. It’s a real honor. And she’s a very good director.”

But the fact that Spotless Minds star Eternal Sunshine is so great with this new ability was “no surprise” to the Australian. “We all knew she would be, but she really is,” Colette said of the actress-turned-director. “It was a really beautiful set, a great atmosphere and an incredible sense of trust and freedom.”

“And she’s a very generous, kind, grounded and funny person,” the Hereditary star added. “And to be honest, none of us wanted it to end.”

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Spall echoed Colette’s sentiments about being a first-time director. He and Winslet were the only ones who had a history before “Goodbye June.” According to Tudam, the 68-year-old British actor first met Winslet while co-starring with the then-19-year-old actress in Hamlet.

He tells PEOPLE that having Winslet on board not only as a scene partner but also as director “felt like a completely natural thing to do.”

“So, when I first worked with her and met her, she struck me as an open, funny, intelligent, self-deprecating person,” Spall said. “And it was very, very honest, and that’s how it matured.”

“And intelligent, that’s another thing,” the Harry Potter actor added. “She’s incredibly intelligent, but it’s never flashy. It’s all completely natural. She’s a great natural actress, but she’s also a very hard-working and versatile actress.”

Spall also told PEOPLE that “everything she learned” from working with “some of the greatest directors on the planet” (Winslet has worked with such greats as James Cameron, Nancy Meyers and Ang Lee) helped her make her directorial debut.

“She’s one of the best actors on the planet,” he said. “And those two elements come together so perfectly that it makes absolute sense for her to direct the film.”

“And oddly enough, it’s a little slow,” Spall added. “I mean, let’s hope she starts doing a lot of things. Because if she asked me to work with her again, I would. I mean, she’s really great.”

The synopsis for Goodbye June, whose cast includes Helen Mirren, Andrea Riseborough, Johnny Flynn, and Fisayo Akinade, tells the story of a family around Christmas when “four adult siblings and their exasperated father are thrown into turmoil by an unexpected change in their mother’s health.”

“But their resourceful mother June (Mirren) orchestrates her decline in her own way, with acerbic humor, blunt honesty, and plenty of love,” the synopsis reads.

Goodbye June is available to stream on Netflix.