Sienna Miller ''smelt of fish for weeks'' while preparing for 'Burnt'.

The 29-year-old actress trained with chef Marcus Wareing to learn the skills needed to play a chef de partie in the movie - in which she stars with Bradley Cooper - but it wasn't always pleasant.

She said: ''I think I cooked 70 turbots in one day - my fingers smelt of fish for weeks.

''Marcus did shout at me during training. 'You can't hold your spoon like a f***ing shovel.' I was [his] favourite pupil.''

The stunning star sported ''a very sweaty face under a white chef's cap'' in the film and found it a ''relief'' not to have to worry about her appearance.

She told Vogue magazine: ''I think, at a certain point, you have to let go of any sense of vanity in films and start playing real character roles. It's a relief actually, for the focus not to be to look glamorous.''

And director John Wells was very impressed with the actress' dedication to the role.

He said: ''She always came to set prepared, ready to work, she trained very, very hard to simulate being a chef.''

As well as her impressive work ethic, Sienna also makes filming fun for those around her.

Bradley said: ''She comes ready to work but also ready to play and makes everyone around her feel at home.''