Bradley Cooper cuddles up to Sienna Miller at NYC premiere of Burnt

Instead, involvement by male allies is needed, and that brings me to actor Bradley Cooper. Supporting Lawrence, his costar in Silver Linings Playbook and American Hustle, Cooper talked about sharing salary information with his female colleagues. But

Sienna, 33, showed off her beautifully slender frame in her intricately-designed white dress – complete with sheer panels and a unique waistband – which boasted a generously low neckline, which plunged almost to her abdomen.

While many of Jennifer Lawrence's peers have commended her for speaking up, her frequent co-star, Bradley Cooper, has vowed to go further—by working with his female co-stars to negotiate equal pay. Cooper told Reuters, “Usually you don't talk about

. Burnt is a story of redemption, both personal and culinary. Bradley Cooper plays Adam Jones, an upmarket chef who had a dramatic meltdown in Paris. We hear about drugs, demons, a fallout with his beloved mentor, all kinds of excess and 

After praising Jennifer Lawrence for her recent essay in which she addressed Hollywood's gender pay disparity, Bradley Cooper has revealed plans to work with his female co-stars on salary negotiations before films go into