She takes few prisoners as a culinary judge on television, but Roz Laws finds Monica Galetti to be charming – even after a trip to the dentist.

I admit it, I’m a little scared as I pick up the phone to talk to Monica Galetti.

She’s the ferocious judge on the BBC series MasterChef: The Professionals, the one whose amazingly mobile face instantly signals her disapproval.

I’m even more nervous when the phone, in the kitchen of Le Gavroche, is answered by her boss, Michel Roux Jr himself.

“Are you sure you want to talk to Monica?” he says. “She’s very grumpy, you know.

“She’s just come back from the dentist.”

Oh dear. I brace myself, but it turns out that Monica could hardly be nicer – and that Michel was joking.

“It’s fine,” she says, with the air of someone used to the high pressure environment of a two-Michelin-starred restaurant and who isn’t going to let a little pain stop her.

“I’ve just had a filling and the front of my mouth is numb. They’ve all been making fun of me.”

You might think it would take a brave person to laugh at stern Monica, but when she’s not concentrating hard on her work, she’s a lot of fun.

Midlanders will be able to see for themselves when she appears at the BBC Good Food Show, which has just started at Birmingham’s NEC and runs until Sunday. Monica is teaching at the MasterChef Cook School and urges people to give it a go, because she won’t bite.

“People are surprised when they meet me, they say ‘Oh my God, you’re smiling!’” she chuckles.

“Of course I am! I love meeting people and I’m very kind to the people at the show. They’re not professional chefs, they’re there to have a good time.

“I am very happy, knowing I’ve taught them something. Some people are brave enough to get up there and have a go when they’ve never cooked before. If they continue cooking at home, that’s great. I love inspiring people.

“This is my fourth time at the show. I love walking around and looking at all the other stands and demonstrations. I’m keen on gardening and there’s an amazing variety of food on offer – I like shopping for things like olive oils.”

Monica, 36, was born in Western Samoa but trained as a chef in New Zealand. She moved across the world for the chance to work with Michel at Le Gavroche, starting as a very junior cook and working her way up to his sous chef.

Her husband, David Galetti, is the restaurant’s head sommelier and they have a five-year-old daughter.

“There’s nothing I wouldn’t do for my team,” says Monica of her colleagues.

“They know when I am absolutely furious with them, but if they have a problem, I’m the first person they come to. I’m very fair.

“I often feel like a mother in the kitchen as well as outside it. But my daughter will tell you, she says ‘Mummy’s not strict!’. I’m a big softie really. Michel is the tough one.”

At this point, I can hear Michel winding Monica up in the background.

“Go away, I’m talking about you!” she says. “As I was saying, you certainly know when you’ve done wrong with him, but he’s not a shouty chef.”

Which of course is the cue for Michel to start shouting.

Their kitchen seems a relatively happy place to work, despite the pressure, heat and seriousness with which they take their jobs.

Monica agrees. “Ours is a decent kitchen to work in. In some, you’re not even allowed to speak.

“I think young people today are too mollycoddled and get a shock when they come into a kitchen environment and see just what it takes to become a chef. They are surprised by how long the hours are. Sometimes we can get five youngsters starting at once and only one will finish their training.”

And what of her ‘victims’ on MasterChef, who face scathing comments like “This plate tastes as bad as it looks”.

“They are professionals who put themselves up for the challenge. If they mess up, people at home are thinking ‘I can do better than that’, and that does annoy me. But I am standing there with my fingers crossed. We want to see them excel, and when they do, we are over the moon.”

* The BBC Good Food Show runs until Sunday. Visit www.bbcgoodfoodshow.com or call 0844 581 1360.