It's been months of nail-biting challenges, but there can only be one winner to walk away with the life-changing title of Australia's MasterChef 2019.

This semifinal is a pressure test set by acclaimed Quay executive chef Peter Gilmore. The three contestants who do the most impressive job recreating the dish will earn their spot in the grand finale.

By the end of the episode, five will become four as the trophy beckons. In a special MasterClass, contestants set their very own mystery box challenge for the judges and Curtis Stone.

Contestants are cooking at Press Club, the brainchild of judge George Calombaris. With the Press Club announcing it will soon close, the top five take to the kitchen to prepare one of the final meals.

Our top five are battling to win an advantage for the next challenge, which could secure them a spot in the semifinal. Contestants can cook whatever they want and decide how much time is on the clock.

The chef director behind Dinner by Heston in Melbourne and London, Ashley Palmer-Watts, sets a lamington-themed pressure test. One contestant will be sent home with only days remaining in the competition.

Each contestant has an ingredient chosen for them by a loved one, with a note explaining their choice. Later, the judges select an ingredient for each contestant to cook with in the invention test.

This pressure test is set by Santiago Fernandez and it's a doozy. The stakes are high and the least impressive cook will be sent home. Plus, catch a masterclass showing off delicious recipes.

This episode's setting is the beautiful Leeuwin Estate Safari Club in Margaret River. Guided by head chef Dan Gedge, our contestants will battle it out in a team challenge.

The winners from the previous two days now cook for an opportunity to fast-track themselves into Finals Week. Round two comes down to the wire as contestants are hungry for the win.

At Wildflower Restaurant in Perth, contestants will cook a five-course degustation featuring an ingredient that chef Matt Sartori has selected.

The remaining contestants fly to Western Australia for a mystery box challenge and later an invention test, using all the great produce WA has to offer.

This episode is the return of the time auction where contestants bid for ingredients with time rather than money. The more time they spend buying ingredients, the less time they have to cook.

Aboard the Q Train travelling restaurant our contestants, in teams, must prepare a vegetarian course using oyster mushrooms, baby zucchini, eggplant or figs. The bottom two teams face elimination.

All contestants will cook with the same ingredient but in a different style. The winner of round one will be cooking against renowned chef Adam D'Sylva for the illustrious immunity pin.

Champion chocolatier Kirsten Tibballs is in the MasterChef kitchen for this episode's pressure test. Three contestants from the previous invention test must recreate Kirsten's apple pie. Who will be going home?

This episode's mystery box involves some deja vu and later, in the invention test, contestants have 60 minutes to create a dish that takes the judges to a moment in time that evokes a particular memory.

The top 10 are joined by the world's top chef Massimo Bottura and asked to cook with ingredients that are very close to Massimo's heart: ones that are frequently disposed of.

The contestants must cook a four-course meal for the Best Diners In The World while showcasing the Best Ingredients In The Country. Little do they know, the diners are their loved ones.

The three winners of the challenges must create a dish featuring Beluga caviar. The best dish will see its maker compete for an immunity pin against Pt Leo Estate chef Phil Wood.

This episode's challenge has been set by special guest Jock Zonfrillo from Restaurant Orana. Contestants must create dishes that showcase one of his favourite native ingredients.

This episode's mystery box holds some of the best-selling ingredients from Coles and along with these, contestants must cook with some of Australia's favourite ingredients: Vegemite, tomato sauce or Milo.

In a very challenging cook, the contestants must make a sweet dish without using refined sugar.

The team challenge requires contestants to create a delicious, sweet dish that is identical in look, texture and flavour to their teammate's dish. Communication is key.

Sweet Week continues with an immunity ice cream challenge. In round two, the best cook will go up against chef Alice Wright.

In a surprise twist, our bottom three contestants from the cereal invention test have been thrown straight into a pressure test. Aprons on: it's time to cook a unique creation by Kate Reid.

Kicking off Sweet Week, molecular master Heston Blumenthal enters the kitchen with a mystery box for the contestants.

Maggie Beer is back for the elimination challenge which will take place over two rounds. In round one, the contestants must celebrate herbs from the garden. In round two, they must feature spices.

Contestants find themselves in the Macedon Ranges for this team challenge: a picnic at Hanging Rock. What will be a surprise is who is the guest chef - none other than the beloved Maggie Beer.

Contestants awake with letter containing special instructions for round one of the immunity cook. The winner will cook off against chef Jesse McTavish from North Bondi Fish.

Three contestants will face the chopping block in an elimination challenge with a surprise twist.

It is the dreaded Everything Box, where contestants must use every one of the eight ingredients. They will have to be extra creative if they want to win a place in the next immunity challenge.

In this episode's elimination, contestants undergo a skills test followed by a seafood platter challenge including raw, fried and steamed elements. MasterClass with judges and Homage restaurant's Ash Martin.

The Queensland trip continues and the teams must cook a barbecue feast to serve 150 Noosa locals. The team that serves the least impressive feast will go into the next elimination.

In round one, contestants must prepare a sweet or savoury dish with one of Queensland's finest ingredients - ginger. The winner will cook off against chef Ben Williamson for an immunity pin.

Contestants must re-create one of Shannon Kellam's signature dishes, but without a recipe. The contestant who re-creates the dish least like Shannon's will be going home.

This episode's mystery box challenge has contestants creating dishes using Queensland's finest ingredients. The judges will taste the five most appealing dishes and the winner will head into an immunity challenge.

Secrets Week closes with the previous episode's losing team facing a blindfolded taste test. The first five to guess incorrectly have a 60-minute open pantry cook, but one last secret will ruffle some feathers.

Each team is allocated a 'secret weapon' and must create a four-course Italian meal for 40 diners. Whichever team serves the least impressive meal will go into the next pressure test.

These immunity rounds involve sauce, secrets and citrus. A contestant will face off against an established chef that will be kept secret from everyone, including the judges, until the very end.

Three contestants face a pressure test and will cook a paella based on an award-winning dish by Leno Lattarulo from Melbourne's Simply Spanish. Simple, right? Wrong. It is Secrets Week, after all.

It's Secrets Week, and, after a quick workshop with Din Tai Fung's Edward Yulianto, our cooks must create a tasty dumpling dish and later invent a dish that incorporates a secret. Shh.

Legends week continues as Yotam Ottolenghi hosts a deli item challenge. The first three contestants to incorrectly name a deli item must cook to stay in the competition. Who will be heading home?

Joined by Yotam Ottolenghi, our contestants are cooking street food for 360 people. Each team must hero a different cuisine, and the least impressive team will be sent into the next elimination.

Matt Sinclair mentors the Immunity cook which uses only equipment from a typical office kitchen. Best dish enters Round 2, where they will compete against culinary legend Donovan Cooke.

This episode's Pressure Test has contestants recreating a dessert from culinary legend Clare Smyth. During four hours of preparation time, there are tears and even a dish that collapses before the judges' eyes.

It's Legends Week and our cooks have to create a dish using Rick Stein's Mystery Box. Later, a fish and potatoes themed Invention Test determines who will face the Immunity Challenge and Pressure Test.

The bottom team from the previous challenge are presented with an array of condiments they must identify correctly. The first five to guess incorrectly head into an elimination cook. Plus, a Masterclass with Nigella.

Contestants are at the State Library of Victoria and given historical menus from two state dinners to inspire a three-course meal. The team who create the least impressive menu will head into the next elimination.

The four best cooks from the mystery box challenge must cook one dish that celebrates custard. The best dish advances to compete against Coskun Uysal, renowned for his restaurant Tulum in Melbourne.

It's pressure test time for the losing team from the previous challenge. The contestants have 90 minutes to cook Nigella's infamous roast chicken with two sides and gravy. Who will fail to impress and be sent home?

It's Nigella Week. MasterChef favourite Nigella Lawson sets the mystery box ingredients. Whoever cooks the best dish heads into immunity, but the rest must compete in a relay invention test.

Round 1, cook with either your favourite or least favourite ingredient. Those who produce the bottom four dishes face Round 2 with their remaining ingredient. Masterclass with George, Poh and more faves.

Contestants cook outside of the kitchen for the first time. Their challenge is to create a feast for volunteers, truckies, farmers and their families impacted by drought in Briagolong.

The winners of the mystery box and invention test face the immunity challenge. History is made when the judges choose who will cook against Young Chef of the Year, Max Sharrad.

Those that failed to impress in the previous episode are facing the dreaded pressure test. Our cooks are charged with recreating a Darren Purchese dessert, and whoever doesn't impress the judges will be going home.

It's mystery box time and our cooks must create a delicious dish using at least one of the elected ingredients. Next up is the black mystery box, but this time, whoever cooks the worst dish is going home.

It's the end of the first week in the kitchen and the winners from the previous challenge will cook for an immunity pin. But it won't be easy: they'll be cooking against chef Curtis Stone.

The pantry is open, there's 75 minutes on the clock, and the contestants are asked to cook the dish they'd cook every day for the rest of their lives if they found themselves on a desert island.

It's day two of auditions and 13 contestants return for a second chance to show the judges they deserve to be in the top 24. With 18 aprons given away yesterday, just six aprons are up for grabs.

Each hopeful cook has 60 minutes to produce their dish. If the judges like the dish, they're through to the next stage. If not, sadly, they're heading home.