John Slattery, Christina Hendricks Remember Philip Seymour Hoffman at 'God's Pocket' Premiere

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Matthew Weiner, Christina Hendricks, Kiernan Shipka and John Slattery

Matthew Weiner and Kiernan Shipka hit the directorial debut of the 'Mad Men' actor at LACMA on Thursday night.

The Los Angeles County Museum of Art rolled out the red carpet on Thursday night for the premiere of God's Pocket, which was directed and co-written by John Slattery and features fellow Mad Men cast member Christina Hendricks with Philip Seymour Hoffman, Richard Jenkins and John Turturro

VIDEO: Christina Hendricks, John Slattery on Finding Time to Film 'God's Pocket'

"Working with him was one of the greatest experiences I ever had creatively -- he's an artist who is the like of which you don't see very often, so when you get a chance to work with somebody like that ... you can't believe how lucky you are," Slattery told The Hollywood Reporter of Hoffman, who was a magnetic factor for the project for his Mad Men co-star Christina Hendricks. "When I gave her the script and told her that he was starring in it, it wasn't really that hard of a decision for her to make, I don't think, because she called me in about an hour, as did most of the people."

God's Pocket tells the story of Mickey (Hoffman) and Jeanie (Hendricks) Scarpato who live in the working-class neighborhood of God's Pocket. When Mickey's stepson Leon (Caleb Landry Jones) is killed in a construction accident, he finds himself stuck in a life-and-death struggle between a body he can't bury, a wife he can't please and a debt he can't pay.

Hendricks was honored to star in Slattery's directorial debut. "Then I read the script, and the script was amazing ... I would have done a YouTube video in his backyard if he asked me, but this ended up being a lot better," said Hendricks, who arrived with husband Geoffrey Arend. She noted that working with Hoffman "was extraordinary and just one of the best environments and situations you can have, so it was the best. It's what you would imagine."

Slattery's AMC cohorts Matthew Weiner andKiernan Shipka, as well as Eddie Marsan, Dana Delany and David Walton, also attended the premiere.

STORY: Philip Seymour Hoffman Film 'God's Pocket' Gets Release Date

Longtime friend and Scandal actorJon Tenney met Slattery in 1988 during Dirty Dozen, and was excited for the film's premiere. "I've known him for a very long time and I love him like a brother, so he directed this, so I got to go and support my brother."

Another close friend Jennifer Grey and husband Agents of SHIELD star Clark Gregg and hit the event, recalling how Slattery pointed out her husband-to-be at Sundance years ago. "I walked in a restaurant and I said, 'Who's that guy?' and he said, 'Oh, that's Clark Gregg. Stay away from him.' And here we are!" Grey said. "I'm here for my beloved John Slattery and my beloved Phil Hoffman."

The celebration continued at the film's after-party at The Church Key restaurant on Sunset Boulevard, where Elisabeth Moss and Jay Ferguson made an appearance. Partygoers sipped on vodka martinis and nibbled on appetizers, including brown sugar brioche donuts, sliders and spicy tuna on a mini rice cake.

God's Pocket opens in theaters May 9.