In US Season 4: When the final six cooks are left, three are invited back to try and win an apron. One of them is Bime, and since no one liked him, no one is clapping when he returns... except Luca.
James: Stop clapping.
Luca: I like Bime!
One challenge in season 4 began with the chefs having to catch a live bird in the pantry, which had been assigned to each of them by the previous challenge's winner. Luca was assigned a turkey. Turkeys are not found in his home country of Italy.
Luca: What is that, a peacock?
Luca trying to catch the turkey and getting intimidated by it instead.
A bunch in the first episode of Masterchef Junior alone...
Gordon trying out Dara's headband and being a Shipper on Deck for two of the kids.
This conversation when Sarah's working on her dish.
Gordon: Who makes the best chefs, girls or guys?
Sarah: Even in the olden days they were cooking and men were just sitting there watching TV. No offense to you.
Gordon: No offense to me? Oh, am I from the olden days?
Sarah: Yes, Chef.
The third episode of Masterchef Junior has three of the children (the top 3 performers of the previous challenge) face off on a whipped cream challenge. The results would be tested by having the kids hold the bowls upside down over the heads of the three judges. Needless to say, some messy fun ensued, including Gordon accidentally swearing after being covered in cream and quickly trying to save face by saying he meant "sugar", and Alexander - the only one of the three whose whipped cream stayed in the bowl - planting the upturned bowl of cream onto Graham's head anyhow.
During the challenge, Sarah screams at Gavin things like "Whip it! Whip like a man!" and "I don't want to see that arm stop moving!", like one seriously hardcore coach.
Dara: "It was really funny, cause Sarah, next to me, she was like, "come on, come on"! And I was, like, this is a different side of Sarah."
Masterchef Junior episode 4: The image of Graham and Joe skipping into the pantry behind the much smaller Sarah.
In Season 3 of the US version, blind chef Christine is often left utterly confused at her fellow contestants' reactions whenever the contents of a mystery box are revealed.
Monti: "Shut your mouth... [Paula Deen is revealed to be underneath the giant mystery box] SHUT YOUR MOUTH!!"
Becky: "It's Paula Deen."
Christine: "SHUT UP"
In the episode which Christine made a Crab Creviche (which is also her Mo A), Gordon asked if she was really blind (as the dish looked as good as it tasted) by asking what his eye color is. Christine told him that she had been asking others to describe the judges to her. Graham immediately declares that he is tall and thin and Joe is short and fat.
Even the Masterchef Junior finale wasn't completely serious.
Gordon: Remind me again, what year were you born in?
Gordon: 2001. So thanks for making me feel like an old fart.
The extra kicker to this? It aired on Gordon's birthday.
Minutes later, Joe tells Alexander who Johnny Cannoli is, since he called his dessert a Cannoli Napoleon.
In Season 2 of the US version, there's Dustin's audition. Gordon's enthusiasm over the sausage roll, especially with the care Dustin puts into it, culminates in him cleaning the plate before Josh and Graham can even taste it.
In the first team challenge of the Spain version of Master Chef Junior, during the cooking process, the judge who is in charge of the blue team sends Noa (the youngest female contestant) to spy on the red team, by having her move over inside a big box with two holes cut out for her to see. Upon noticing, the judge aiding the red team picks out Aimar (the youngest male contestant) to stand near the box and talk about how their red team is "doing terribly", which Noa believes and lets her judge-in-charge know, making him (and herself) practically squee in delight. Cue the judge-in-charge for the red team sending out Aimar, having changed his red apron for a blue one, into the blue kitchen to sabotage them by changing the temperature in the ovens, only for several members of the blue team to grab on to Aimar, literally drag him out of their kitchen and back into his.
In a UK episode of the 2014 season, judge Greg demonstrates the disappointing thickness of a contestant's rice pudding by holding the bowl upside down over his head, and watching it stick.