Dame Helen in her role as the very strict and traditional French chef.

Dame Helen Mirren has confessed she cannot resist mashed potato and has to indulge occasionally, despite believing it is bad for her figure.

The 69-year-old actress plays a chef in new film The Hundred-Foot Journey but recently said she knew the “torture” of constantly dieting for movie roles.

The Oscar-winning actress joined co-stars Om Puri and Manish Dayal on the red carpet for the UK gala screening at the Curzon Mayfair in London.

The film – directed by Swedish film-maker Lasse Hallström, who directed Chocolat and Salmon Fishing in the Yemen – is the big screen adaptation of Richard C. Morais’s bestselling book about the rivalry between an Indian family and a French chef, after the family open an Indian restaurant 100 feet across the street from a Michelin-starred French eatery.

Asked to name her guilty pleasures Dame Helen said: “I love cream, I love mashed potatoes. I like Christmas pudding, I like Christmas pudding with butter on it. Can you imagine? I really love very, very fattening food so occasionally I indulge myself, but you do have to be careful.”

She revealed she learned how to break eggs the professional way while making the film, but added: “I ignored the advice and broke them my own way.”

The French restaurant is run by very strict and traditional chef Madame Mallory, played by Dame Helen, who becomes a reluctant mentor to aspiring Indian cook Hassan Kadam (Dayal).

East is East star Puri, 63, plays his father, who strikes up a love-hate relationship with Madame Mallory.

Puri said: “It’s like a dream project for me: Spielberg and Oprah producing the film, and Lasse Hallström, a fantastic director, and our very darling of Britain, Dame Helen Mirren – working opposite her was a great reward for me.”

The pair share a dancing scene in the movie and Puri revealed: “She taught me.”

The Hundred-Foot Journey is produced by Steven Spielberg and Oprah Winfrey.