Spoiler warning: This article contains spoilers about the premiere episode of MasterChef Australia that some readers may prefer to avoid.

The highly-anticipated 12th season of MasterChef Australia premiered on Channel 10 tonight with an all-new judging panel and a cast of returning contestants.

The show began with a look back at the past 10 years of the series and included a touching tribute to former hosts Gary Mehigan, George Calombaris and Matt Preston, all of whom stepped down ahead of the new run.

This season has the tagline Back To Win and features 24 contestants from the past 11 seasons competing for another shot at glory.

Surprising the contestants as they arrived in the kitchen for the first time was Gordon Ramsay, who announced that he would be part of the judging panel for the entire first week.

Ramsay went on to introduce the three new judges - season four winner Andy Allen, food writer Melissa Leong and Scottish chef Jock Zonfrillo, himself a former apprentice of Ramsay.

The contestants were then set the challenge of competing for the first - and in a twist, the season's only - immunity pin by cooking a dish that would be worthy of featuring in the final.

After all the dishes had been presented, the judges whittled it down to a top four: Reynold Poernomo, Dani Venn, Laura Sharrad and Emelia Jackson.

"You four didn't just understand the brief, you knocked it out the park and then elevated it," Ramsay told them. "If I could give out four pins tonight you four would be wearing them."

Zonfrillo then revealed the top two: Dani's Sri Lankan-inspired feast comprising a mud crab curry, pineapple curry and homemade roti, and Reynold's 'White Noise' dessert, involving a jasmine gelato, coconut ganache and a white chocolate crumble.

"I've got to say, we'll remember your dishes for a long time," he added. "The discussion we've just had the last 10 minutes was ferocious. It was very hard to slice a piece of paper between you two, really. But today it's going to the dish we'd like to eat again and again and again."

Dani was then unveiled as the winner of the season's only immunity pin - and with her tally of two pins during season three, became the first ever contestant to hold three pins.

"It's the best way to start this competition," she gushed. "I'm here as a serious contender. It means so much to me."

MasterChef Australia continues Tuesday night on 10.