IN WHAT was called by food critic Matt Preston "the greatest comeback ever seen in MasterChef history", Bowraville's Billie McKay was crowned Australia's MasterChef 2015.

Trailing by four points behind fellow finalist Georgia in the first two rounds of the grand final, Billie had to excel at the biggest pressure test ever devised for the food-lovers TV series.

Chef Heston Blumenthal presented the "most wicked and difficult pressure test dish in the history of MasterChef", Heston's "Botrytis Cinerea" from his UK restaurant The Fat Duck, a 55-step, 17 element, five-hour monstrosity of a recipe.

There were 40 points to be won in the final test.

Once again Billie showed the resilience, poise and calm that was her trademark during season seven of MasterChef.

"I am stoked I got there, I really didn't think I would," she said.

"It felt quite unachievable, really, coming back from four points behind, but I somehow managed to do that, so I am really, really stoked."

The new MasterChef winner said behind her calm manner she felt the pressure of the grand final.

"I think I must be pretty good at not showing it because, really, underneath I felt really stressed and quite overwhelmed," she said.

"It's a skill I might take with me."

Still overwhelmed after the win, Billie confirmed she had taken Chef Heston Blumenthal's surprise offer of a job at his UK restaurant The Fat Duck.

Billie will fly to the United Kingdom with her partner Haydn to take up the opportunity.

"It will be in the next couple of months. I'll be leaving and Haydn is coming with me."

Billie, who grew up on a dairy farm at Bowraville, has lived in Ballina for two-and-a-half years after meeting Haydn.

Her proud mum Alison said Billie took to the kitchen from a young age and quickly showed a flair for cooking.

She grew up on a dairy farm preparing meals for dad David, her sisters Georgie and Frankie and brother Joe.

"Billie loved learning to cook from a young age and she always helped when it came to cooking cakes and biscuits," Alison said.

"As she got older she would 'bags' to stay down at the house and cook the dinner, instead of helping with the milking in the arvo.

"We knew recently that she made it to the final two, but we weren't allowed to say anything.

"Billie talks about opening a restaurant in a regional area somewhere and I'm sure she'll do that."