Watching Dame Helen Mirren make a cup of tea is a surreal experience.

As the poised Oscar winner, looking glam today in a Dolce & Gabbana fitted black dress, pours a cup of English Breakfast from a teapot before adding milk, she remarks: “Americans don’t know how to make tea. You have to teach them all the time. They always put the teabag on the side of a cup of lukewarm water.”

Mirren’s tea-making skills are so renowned in Hollywood, even American director Jason Winer undertook painstaking research into tea etiquette before meeting up to persuade her to appear in his remake of Arthur.

In Winer’s version of Arthur, which sees Russell Brand take on the titular role made famous by Dudley Moore, Mirren plays frumpily-dressed nanny Hobson.

“I didn’t want to look like a nanny,” she chuckles. “...So I thought I’d look like a very bad nanny!”

Like her part in The Tempest, where sorcerer Prospero was turned into a woman, Mirren’s role of Hobson was originally a butler played by Sir John Gielgud in the 1981 version, and won him an Oscar for Best Supporting Actor.

“I was nervous about stepping into John Gielgud’s very big boots. But what can you do? You go in and do your best,” she says, shrugging.

The original film was a huge success – it was the fourth biggest box office hit in the US that year and scooped two Oscars – but Mirren wasn’t a fan.

“I didn’t particularly love the original, which made it easier for me to contemplate doing the re-envisioning of Arthur,” she admits.

“Don’t get me wrong, Dudley was a genius of comedy, but I found the whole approach to alcoholism insulting to women.”

Her Tempest co-star Brand plays the booze-loving playboy billionaire, previously portrayed by Dudley Moore.

“Arthur is the man-child to end all man-children. For a number of reasons, he’s been incapable of fully growing up. Though he’s enormously kind and generous at heart, he’s rudderless,” she says.

The 65-year-old had immense fun with the funnyman, and is in awe of his talent.

“I loved watching Russell do his stuff – it was a pleasure to be on the set and witness his amazing talent. Any scene where I could sit back and just observe his sarcasm was great,” she says.