What do you get when you put 22 amateur cooks, five MasterChef judges, and 40 former contestants in one room together? If you answered, “a breach of fire safety regulations”, you’re correct. But you also get a MasterChef service challenge, in which two teams will compete tooth and claw to tear their hated rivals apart.

The amateurs are assigned to their teams: one purple, one burgundy, which seems a bit pretentious. Jamie will be in charge of the kitchen, and makes a speech informing the cooks that they need to perform as “I don’t want to look like a plonker”. Some would say that ship sailed around his fourth TV series, but we would not be so uncharitable here.

Then, suddenly, the doors open and in pour 40 MasterChef legends – or at least, 40 people who have been on MasterChef before. Frankly, if there are 40 of them, that seems to devalue the term “legend” a bit. Still, all the greats are here: Julie! Mindy! Sashi! That guy with the hair! The woman who did the thing that one time!

Each team must create a three-course meal. Each course will have to contain a judge-selected ingredient: mushrooms for entrée, cashews and capsicums for main, and grapefruit for dessert. The meal will be served to the 40 ex-MasterCheffers, whose opinion of the food will be utterly meaningless. The team that does best will cook for immunity from the first elimination.

The teams gather to plan. On the burgundy team, Sav immediately declares herself a big personality and therefore well-suited to shouting and ignoring what anyone else says. She relates how her contingency plans have contingency plans, and reveals that she is also a sponge. Doubts about her sanity begin to set in.

Over on the purple team, the captain is Mimi, who apparently is someone who is on this show. Mimi is a high school teacher, a job she says she loves. “The kids give me so much joy,” she says, which is why she has gone on MasterChef in a desperate attempt to get away from them forever.

Cooking begins. Both teams are already hours behind. The ex-contestants are up on the gantry, pondering that eternal question: what is a “gantry”? They are worried by the complete absence on the burgundy team of any urgency or signs of psychological breakdown. Julie focuses on Harry. “Hat dude! Hat dude!” she yells, infuriated by his laconic demeanour. Julie, of course, famously hates hats: MasterChef fans will remember the time in Season One when she ripped the hat from Chris’s head and deep-fried it. Harry is oblivious to her cries, though, and continues his regular routine of wandering aimlessly around the kitchen, unable to shake the nagging feeling that he’s supposed to be doing something, but can’t remember what.

The ex-contestants are up on the gantry, pondering that eternal question: what is a “gantry”?

On the purple team Mimi admits she’s struggling to bring together the many disparate voices, and so has had to quietly execute several of her teammates in the name of harmony. Disaster strikes as the cashews begin to burn. The red team’s laidback attitude not looking so silly now, is it?

We break for a getting-to-know you segment. Meet Sumeet. “My superpower is spices,” she claims, in a direct lift from the Marvel Cinematic Universe’s Phase Five. She believes the judges will never have tasted anything like her curry before, in what sounds a lot like a threat.

Jamie gives Lachlan advice on filleting fish. “Long convincing strokes, always angling towards the bone,” he says, as onlookers begin to doubt that he’s still talking about fish. Meanwhile, burgundy’s Harry and Snezana ask Andy if it’s okay to serve just one scallop per diner for entree. Andy gently lets them know that this is a service challenge, not a refugee camp, and maybe deliberately starving the guests isn’t the optimum move.

Sofia and Poh check in on Sav. She admits that she is vomiting internally. Sofia and Poh laugh instead of summoning emergency medical aid. We now cut to a basketball game.

The basketball game is part of the at-home montage of Darrsh, for who basketball is a metaphor for dessert. He is an expert at desserts, though as the montage demonstrates, making dessert at home is very different to making it on MasterChef: at home, he makes desserts in slow motion.

The judges are concerned about the purple team, whose indecision is in stark contrast to the calm control of the burgundies. Jamie takes Mimi aside to ask her what the hell. The purple team needs to decide just what they’re doing for main course. Mimi absorbs his advice and enters a fugue state. She tells her charges to cut the cauliflower cream and make something nice instead. The purples snap into action with a newfound sense of purpose, thanks to Mimi’s teacherly experience and finely honed abuse.

With 30 minutes until service, Andy discovers the purple team has yet to roll their dumplings, which is not a euphemism. “This scares me a lot,” says Andy, who suffers from a rare phobia of late dumplings. As always, MasterChef is an invaluable learning experience for contestants: the purple team today has learned one of the secrets of professional cookery: it helps a lot to make the food before you serve it.

The ex-contestants sit down to eat with the smugness of people who know they’re not cooking. Service begins. The red team slings scallops while the purples dole out dumplings. Sav carefully makes sure each scallop has a flower on top, knowing that the key to fine dining is having inedible garbage on the plate.

The judges try the purple entrée. “It smells nice?” says Poh, hardly daring to believe it. “A super commendable effort,” says Andy, so you know it sucked. He says “commend” several more times, having just learned the word this morning and wanting to put it to use.

The burgundy team’s entrée arrives. “That’s a brilliant restaurant-level dish for me,” says Sofia, tactfully omitting that the restaurant in question is the Red Rooster at Plumpton. Meanwhile, at the legends’ tables, an Irish guy says he loves it. I wonder who that guy was.

Main course time. Mimi tastes her main one last time. She discovers it tastes like a burning tyre, but too late to do anything now. The purple team takes infinite care plating up their lamb backstrap, with the result that nobody gets any for a good six hours. From the balcony, the entree team yell unhelpful instructions.

The judges dig in to the purples’ lamb. It makes Jean-Christophe cough. “They’ve tried to go to France, they’ve tried to go to the Mediterranean,” says Sofia, disapproving of the team’s attempts to escape the show. The lamb is cooked well – “I commend them on that,” says Poh, catching Andy’s disease – but the judges are agreed that overall the purple team has cooked badly and are bad people.

Along comes the burgundy team’s fish curry, which is so good that the judges get even angrier at the purple team’s reckless incompetence. Andy believes the burgundy team should be commended. In the dining room, a blonde lady says the curry was delicious, but refuses to reveal her identity.

Finally, it is dessert time. Purple serves a grapefruit-infused sponge – I assume that means a cake, but not totally certain. Burgundy serves meringue with all sorts of fancy nonsense splattered over it. Lily and Alex agree that the meringue is sexy, which is frankly disturbing.

The meringue is served. “Cucumbers!” exclaims Poh, possibly having some kind of episode. The dish is a success. “It’s petite,” says Jean-Christopher, apparently not realising that we speak English in this country, mate. On the other hand, the purple team’s cake is, according to the French chef, “well-executed”, so they’re screwed. Both desserts were beautiful, according to MasterChef legend Jess and a man with glasses sitting next to her.

Finally, it is all over. The judges congratulate the burgundy team on their skill and finesse, and congratulate the purple team on bravely persevering despite being a lot worse at cooking than the burgundy team. Unsurprisingly, just like in the Bay of Pigs, it’s a win for the reds.

And so, as the burgundy team prepare to turn on each other with the savagery of wild beasts in the immunity challenge, and the purple team go away wondering how they can possibly go on, and the MasterChef legends walk out into the night still not sure what the point of them being here tonight was, we can only ask: what next, on the show that never stops serving up piping hot slices of excitement?