Australia's best amateur cook wants to open a little restaurant on the NSW Central Coast after winning MasterChef.

Almost four million people tuned in to see NSW mother-of-three Julie Goodwin win $100,000 and a cookbook deal along with the title of Australia's first MasterChef.

More than 3.7 million viewers watched Julie Goodwin be crowned the winner of MasterChef Australia, making it the most watched TV non-sporting event since ratings began.

An average national audience of 3.745 million watched the winner's announcement, while 3.31 million tuned into the whole two hour finale on the Ten Network on Sunday.

It was an even bigger audience than had been predicted.

The previous non-sport record was held by the Australian Idol verdict in 2004, which scored 3.3 million viewers.

The most watched item on television is the 2005 Australian Open men's final when Marat Safin defeated Lleyton Hewitt, which had just over four million viewers.

The Central Coast resident now hopes to open her own restaurant, where she wants to serve "good, unpretentious food" and make her customers feel loved.

Goodwin, a 39-year-old who runs her own IT business, whipped up a sage and garlic chicken and despite appearing flustered did a fine job of replicating celebrity chef Matt Moran's signature chocolate cake dish to take out the top prize on Network Ten's Masterchef program on Sunday night.

She was one of 20 finalists whittled down from 7,500 applicants who auditioned for the first series of the program, which involves amateur cooks preparing dishes for chefs and food critics.

Sunday night's finale saw Goodwin go head-to-head with Poh Ling Yeow, a 35-year-old artist from Adelaide.

They were required to complete three challenges - to correctly name the ingredients of chef and judge Gary Mehigan's beef bourguignon, cook a whole chicken to restaurant standard, and replicate Moran's chocolate Assiette dessert dish.

"It's the most important plate of food I've ever put in front of anyone because it's my future," Goodwin said nervously as she finished fussing with the tricky dessert.

The judges were delighted.

"The sorbet is absolutely beautiful," judge George Calombaris said.

Goodwin, who specialises in Australian home-style cooking, admitted she had struggled to shake off the perception of being a "home cook".

Judge Matt Preston told her she had moved from a home cook to a restaurant cook.

Goodwin was just one point ahead of Ling Yeow in the taste test challenge, and scored two points more than her competitor for her chicken dish, but at the end of round three was the clear winner of the evening, scoring 82 out of a possible 100 points.

Ling Yeow scored 75.

Graciously acknowledging her new role as Australia's first ever Masterchef, Julie said she wanted to open "a little restaurant" on the Central Coast that people would love to come to.

"I just want to serve good food, unpretentious food," she said.

"I just want it to be a warm and welcoming place that people love to be in and I want to cook food, when people leave my restaurant I want them to feel like they've been loved."

Goodwin won $100,000 and a cookbook deal with Random House as part of her prize.

As runner-up for the first Masterchef series, Ling Yeow got an offer she couldn't refuse.

Curtis Stone, one of the guest judges on Sunday night and a successful international chef, told her he thought she had "a real art" with the way she put food on a plate.

"I'm going back to LA to shoot and if you'd like I'll extend an invitation and pay for your flight to come over and spend a week on set with my team," he said.

Based on a UK format, Masterchef has drawn millions of viewers since it hit television screens in April.

Sunday's finale was predicted to attract anywhere between 2.5 and three million viewers.

Applications for a second series have opened.

The two-hour finale was pre-recorded on July 2 in Sydney.

Cast, crew and post-production staff signed confidentiality agreements ensuring the result would not be spoilt ahead of Sunday's broadcast.

News Ltd's The Daily Telegraph website initially erroneously reported that Ling Yeow had won, before replacing its story.