Archive copy by Jenni Baden Howard

‘I have to eat,’ says the Madrid-born and now Hollywood-based star, who is tucking into a hearty salad when we meet. ‘When I’m working, I have to eat a lot because I need the energy.’

Cruz and her distinctly modest entourage - her publicist and two representatives from Ralph Lauren fragrances, for whom she is the “face” of the fresh, sexy Glamorous scent - are gathered in the “Terrasse des Ambassadeurs” on the top floor of the Palais de Festival. It is here that Luc Besson’s film Fanfan La Tulipe, in which Cruz stars with Vincent Perez, opened this year’s Festival. There is no sign of the other Cruise, since - as Cruz made clear at a press conference, in no uncertain terms - Tom couldn’t make it because he is working (filming The Last Samurai in New Zealand) and questions about their endlessly documented relationship will get short shrift.

Cruz’s rooftop press camp is well insulated against the buzz and bustle of the packed promenade below, where the Pink Panther film soundtrack is being piped through open-air speakers, the most serious yachts are moored off-shore (the biggest, with a helicopter on board, is rumoured to belong to Will Smith), hotel facades are emblazoned with movie billboards and the lifts are sponsored by Nokia.

Lunch break over, Cruz is ready to talk. By her own admission, she is ‘very lucky’ that she does not have to follow a particularly strict diet - although she tried being a vegetarian for three years - in order to maintain her petite-but-curvy, ballet dancer’s physique (Cruz trained for nine years at the National Conservatory in Spain, before taking up drama, and her younger sister, Monica, is a professional flamenco dancer who has toured with Joaquin Cortés). ‘I try to eat healthy food, because I love fried food and bad things,’ she says. ‘And I love oil. You give me a plate of bread, some oil and salt and I’m happy. But, of course, you can’t eat like that all the time.’ Such endearingly candid revelations are typical of Cruz, who won over sleep-deprived women everywhere when she went on record as saying she needs her beauty sleep - lots of it. ‘Sleep makes me feel good,’ she admits. ‘When I don’t sleep, I’m a mess.’

Needless to say, Cruz looks anything but a mess. Just as it appears on-screen, her beauty is - forgive the unoriginal comparisons - part Sophia Loren-sultry, part Audrey Hepburn-fragile. She is wearing a floaty, caramel-gold silk dress and a simple knitted cardigan - both from Ralph Lauren’s autumn/winter 2003 collection. It couldn’t be a more different look from the dramatic John Galliano gown Cruz wore two days earlier when she sashayed down the red carpet for the screening of Fanfan. The film is a remake of a 1950s, Three Muskateers-style romantic adventure starring Gina Lollabrigida.

‘John Galliano offered to create a dress for me. I admire him very much,’ says Cruz. ‘He did all the sketches, and they were amazing. He made this beautiful dress himself, and the necklace, too.’

Cruz wore her hair swept into a shiny, very Spanish, centre-parted chignon, complemented by stunning, smoky-eyed make-up. ‘My make-up artist, Whitney James, did it for me. She’s one of my best friends. We always travel together and we have a lot of fun.’ As for indulging in any pre-red carpet beauty treatments, forget it. ‘That’s not realistic. You think “oh, I want to do it this time”, and then you get there and there’s no time,’ says Cruz. ‘For the Fanfan screening, I had a half-hour massage and then it was time to get my make-up done. But massage helps me a lot when I’m doing so much travelling.’

Today, Cruz’s look is understated but “finished”. Her impossibly dark brown eyes are enhanced with a simple slick of eyeliner, and her hair falls in shoulder-skimming, raven ringlets. Her trademark mane was cut - Cruz’s suggestion - for her role as a Spanish refugee in the film Head In The Clouds.

Due for release early next year, the romantic drama, set in England during the 1930s, also stars Charlize Theron. Rather than opt for a wig, Cruz felt that going for the chop would be better. ‘I wear my hair to favour the character - can you say “favour” the character?’ Whatever I feel the character needs. I’m lucky, because my hair is really strong and I can do a lot of things to it and it stands it. But, because I spend so many hours in the hair and make-up chair, I don’t really wear any make-up when I’m not working. And I love my jeans - I wear them almost every day.’

The filming of Head In The Clouds overlapped with the shooting of Gothica, a contemporary horror/thriller in which Cruz appears alongside Halle Berry and Robert Downey Jr. Directed by Amélie star Matthieu Kassowitz, the film is set in a mental institution and is also due for release next year. ‘I like to take risks. I don’t want to feel like I’m doing something I’ve done before,’ says Cruz. ‘Now I’m shooting two movies at the same time, with very different characters, and I’m happy about that. People are giving me that trust. But I fight for that. You have to say no to a lot of things, but it’s worth it.’

It’s easy to forget that Cruz was a household name in Spain long before Cruise and director Cameron Crowe cast her in Vanilla Sky, having visited her on the set of Captain Corelli’s Mandolin, after which she took Tinseltown by storm. Since making her film debut in Jamon, Jamon, at the age of seventeen, Cruz has appeared in critically acclaimed films such as Pedro Almodovar’s All About My Mother, Live Flesh and Woman On Top (Cruz’s childhood heroine was fellow Almodovar muse, Victoria Abril), and she scooped the equivalent of a Spanish oscar for her role in Fernando Trueba’s The Girl Of Your Dreams.

Although home is now Beverly Hills, Cruz is extremely close to her friends and family in Spain. ‘I go to see them a lot, and they come to visit me. When I go there, we make very long dinners, for five or six hours, and we sit at the table talking, talking, talking,’ she says wistfully. ‘For me, that’s going out. I don’t like going to discos or parties. I don’t like the noise. I like being at a table when I can hear people. I’m trying to create that in L.A., because it’s one of the things I miss the most: long, late dinners with friends.’

Has she found that Hollywood attitudes to health and beauty and glamour differ hugely to those back home? ‘It very much depends on the person,’ she says frankly. ‘Only that in L.A., everybody exercises and that makes it easier to go to the gym. Because everyone’s doing it, it’s like there’s an energy ...’ That said, Cruz prefers the slow, controlled pace of Pilates. ‘I love Pilates. It was created for dancers, and it works all the muscles that you don’t work as a dancer. It makes these muscles stronger and it’s a really good, complete (form of) exercise. And I love yoga, but I haven’t done it for a while.’

According to Cruz, the years she spent at the ballet barré have left her with more than that immediately recognisable, ballerina’s poise. ‘It’s also given me a lot of discipline,’ she says. ‘It was really hard to train - much harder than making movies. I remember once my feet were bleeding, and I said “no, I can’t” (go on), and the teacher said “keep going - and smile”. You can’t make it as a professional dancer unless you learn how to dance when your feet are bleeding. Also, when you are making movies, you have to do a happy scene when you are sad, and the opposite. You can’t change it.’

Despite her relentless schedule, Cruz makes time for charity work. She donated her entire fee for her role in Stephen Frears’s The Hi-Lo Country - her first English-speaking film - to Mother Teresa’s Calcutta Sanctuary, having spent a week at the children’s home as a volunteer. She also works closely with the Madrid-based Sabena Foundation, which rescues homeless girls in Calcutta.

‘I was very lucky to meet Mother Teresa,’ says Cruz. ‘She put me to work immediately, and I felt very privileged that I could see with my own eyes situations that unfortunately are there. I don’t feel I did anything for her. But, thanks to my work as an actress, I get asked to do things like that. If, by going somewhere, it means that someone’s going to build a hospital for those kids .... if it helps one person, it’s worth it.’

While Cruz is the perfect “spokesmodel” for Glamorous - a lighter, subtly sparkly version of the scent will launch this autumn - she comes across as a star who is keeping her (unbloodied) feet firmly on the ground. You get the feeling that she can’t wait to get back into her favourite jeans, and sit down to a long, lazy dinner with her nearest and dearest. And a very big basket of bread.

• Ralph Lauren’s Glamorous Shimmer will be available from September.