“The Debut” ended London Film Festival on a high note Sunday night as director Jesse Eisenberg and star Julianne Moore gushed over each other to a packed audience at the Royal Festival Hall.

“I mean, this movie stars my favorite person, Julianne Moore,” Eisenberg began as the duo came onstage to introduce the musical comedy. “But ironically, strangely, it’s the story of my life.”

Written and directed by Eisenberg, “The Debut” stars Moore as Mona Friedman, a shy New Jersey housewife who auditions for a part in her local theater’s production of a fictional musical called “Nosy Neighbors.” After she’s cast in the supporting role of Miss Danielle, Friedman’s life begins to unravel as she becomes more consumed with playing the part and falls under the spell of director Jerry Blankenbuehler (Paul Giamatti).

Eisenberg said he started doing community theater when he was “7 years old and miserable,” and it changed his life forever. “I wanted to write about that experience in my life, but I could only picture Julianne, to the point where I was writing it and she was inspiring me,” he added. “It’s the most thrilling experience to watch her and edit her for two years.”

Moore, wearing a chic black gown, returned the praise. She called “The Debut” an “incredible gift” and said it’s “one of the best scripts I’ve ever read in my entire life.”

“It was such an honor to receive it and such a thrill to go to work every day and to get to do this incredible part with these tremendous actors,” she said, adding of Eisenberg: “He’s a beautiful writer, exemplary director and just a great talent.”

In response, Eisenberg quipped: “I just want to note that the only time I’m called beautiful, it’s about writing.”

“The Debut” team fully leaned in for the U.K. premiere, with each guest finding a fake Playbill for “Nosy Neighbors” at their seat. During the screening, there was plenty of audible laughter and several rounds of applause for high points in Moore’s campy performance.

Sadly, Eisenberg said that Giamatti could not attend as he has COVID-19. “I wish he could be here. He is the greatest guy and you would love to hear him talk,” he said. “Paul’s been my favorite actor since I’m young, Julianne’s been my favorite actress since I’m young.”

Alongside Moore and Giamatti, “The Debut” also stars Eisenberg, Halle Bailey, Colton Ryan and Bonnie Milligan as actors in the musical. Bernadette Peters, Lilli Cooper, Maulik Pancholy and Havana Rose Liu round out the cast.

Of acting with his childhood heroes, Eisenberg said it was “the thrill of a lifetime” but also “very strange.”

“I was spending so much time enthralled with them, and then it was like Michael Jordan said, ‘Here, you take the ball!’ And I’m like, ‘What is this thing?’ So it was so distracting to me. I hope to never act alongside them again,” he joked. “I was my worst self.”

“The Debut” premiered at Telluride Film Festival last month, where it earned rave reviews and Oscar buzz for leading lady Moore. In Variety‘s review, chief film critic Owen Gleiberman wrote: “‘The Debut,’ a small-town-theater comedy rooted in big ideas, is a funny and dizzying mind-bender. It’s like ‘Waiting for Guffman’ made by the Coen brothers at their most rivetingly unhinged.”

“The Debut” is set to hit theaters on Dec. 11 via A24.