She's a Samoan-born Wellingtonian but she's holding her own on a British food show. Introducing chef Monica Galetti.

Considering her fearsome reputation as "Miss Nasty" on BBC2's MasterChef: The Professionals, I'm concerned that Monica Galetti will dismiss me like an errant contestant when I meet her one morning at La Gavroche, Michel Roux Jnr's high-end Mayfair restaurant where she has worked for the past decade.

But the Samoan-born Wellingtonian greets me warmly, introducing me to head chef Rachel Humphrey as she leads me through the kitchen, where preparations are frantically under way for the day's lunch service.

Settling down at the table where Roux, Humphrey, Galetti, her husband head sommelier David Galetti and other members of the management team will later gather for their daily lunch meeting, she insists that she is a down to earth Kiwi at heart.

"I'm told that I'm quite harsh and a bit of a Simon Cowell when I'm on the television," she laughs. "That's probably because I'm a woman, as Michel also says some quite harsh things and he doesn't get accused of being overly nasty. They think he's quite lovely."

Writing in The Observer, renowned food critic Jay Rayner recently noted how "her intense stare, her inability to hide even for a second her disapproval on her intensively mobile face' has turned Galetti into a cult figure. But after some of the disastrous mishaps that frequently befall the feckless contestants, you have to wonder how she manages to stay so stoic.

"I'm not allowed to say anything while they're performing their tasks unless they're going to stab themselves or something," she says with a wry smile. "You're standing there, watching them balls something up and you can't speak so, of course, it comes out on your face. You just can't hold it in."

The 35-year-old has come a long way since her days as a student at Upper Hutt's Central Institute of Technology in the early 1990s. "A lot of my friends were interested in tourism and travel so I applied for a hospitality diploma, for which you have to spend some time in the kitchen and some time in the front of house," she recalls. "As soon as I walked into the kitchen I knew where I belonged and I've never looked back since."

Back then, working for a legendary chef like Michel Roux Jr would have been beyond her wildest dreams. "There isn't such a hierarchy in the cooking world in New Zealand as there is in the UK and Europe," she says.

"You always heard about the Roux family and it's just amazing to even set foot in their kitchen. It's been the hardest thing I've ever done in my career but it's been the most rewarding."

After graduating, Galetti worked at Lower Hutt restaurant Timothy's. The owner sent her to culinary competitions in Australia, America and Europe. "That's when the travel bug really hit me," she says. "After a trip to England, I realised that London was where I wanted to be. It really opened my eyes and I wanted to go back and try it for a couple of years."

Galetti sent her CV to several leading restaurateurs including Raymond Blanc and Michel's cousin Alain Roux, who runs the Waterside Inn in Bray. "Michel was the first to reply so I took it straight away," says Galetti. "I've been working for him ever since."

After five years working in Wellington, Galetti had reached chef de partie status. But following her move to London in 2000, she was forced to start again from the bottom as a lowly first commis, a position "that doesn't even exist in New Zealand".

She progressed rapidly through the different sections, becoming not only the first woman to cook the fish and the meat but also La Gavroche's inaugural female sous chef. "That was quite an accolade to achieve," says Galetti, who ranks immediately below head chef Humphrey. "We've got a history together. We go back a long way."

However, no other women has since reached such lofty heights at La Gavroche; something that Galetti partly attributes to the tough working conditions. "It's such a hard, male dominated industry and it's really full-on," she says. "You've got to be able to carry the weight of the heavy pans and you've got a head chef yelling at you when you make a mistake. I find that women have this thing where they hold in their anger and then tear up while men will punch a wall or walk out altogether."

As Galetti knows only too well, it also isn't an easy job to balance with the commitments of a young family. "I have a four-year-old daughter and I'm as passionate about raising her as I am about cooking," she says.

"At the moment I only work four days a week, which still amounts to 40 hours. But who is going to take me on as a part-time head chef?"

Galetti will soon have to find room in her hectic schedule for the next series of MasterChef: The Professionals, which begins filming in May. "I got that through Michel," she says.

"After he did the first series in 2008, the BBC wanted to extend the programme. But he didn't have the extra time to film it all so he suggested having someone else overseeing the preliminary rounds. He put me forward and I got the part. It was nerve-racking and I didn't enjoy it at first. I thought Michel was mad to suggest me but he's always had faith in me when I haven't."

Since launching in 1991, MasterChef has not only given rise to MasterChef: The Professionals but also Celebrity MasterChef and Junior MasterChef. Versions of the show have also been produced in several different countries including America, Israel, India and here in New Zealand.

"Like most people in the industry, I was never a great follower of the original show," says Galetti, who believes that the Professionals series provides a unique insight into her work.

"We explain more about how it's done. Instead of somebody just cooking something, we show how to prepare a rabbit instead of just giving them a cut of meat and telling them to cook something from it. You can then go to the supermarket and not be afraid to buy something different and cook something from it."

Along with Roux and MasterChef hosts John Torode and Gregg Wallace, Galetti filmed a special episode for UK telethon Comic Relief, which saw three TV personalities preparing a meal for British PM David Cameron.

"He's a very lovely man," she says. "Of course, you have to see the politician as a politician but as a man he has a great sense of humour."

Galetti is now developing a proposal for her first book, which she hopes will be published early next year. "It will be about taking what I do and simplifying it for everyday life," she says.

"Adapting the techniques that we use in the kitchen to make it easier at home if you're preparing a meal for the family and you don't want to be behind the stove for hours. So you put everything in the pot and off you go. There will also be some of the food that I grew up with, such as Pacific Island cooking."