The episode with Paula Deen in Season 3 had this crossing over with Tear Jerker. The remaining contestants were told to look in their drawers, where they found pictures of their family (whom they hadn't seen in a long time) along with a letter.
Season 3 episode 5 of the US version contestants had to make an apple pie. Christine, who is blind, was plagued with doubt on how her pie turned out and was convinced it was a mess. Chef Ramsay proceeded to describe to her how beautiful her pie was, scraping the top so she could hear how good the crust turned out, and confirmed her pie tasted delicious. He told Christine to stop doubting herself and be bold, and congratulated her on a job well done.
Adding to the heartwarming, she ended up winning the whole damn competition.
The contestants were undergoing a pressure test because they lost as a team to the other group in the preceding competition. When team captain Frank is told he can pick any member of the team to escape the pressure test, Chef Ramsay adds the fact that he can pick himself. Frank immediately responds that there's no way he would because he was responsible for the outcome and it was partly his fault they lost the competition to begin with. Then when he tries to pick Felix, who's idea had been better than Frank's, she too refuses. This happens again with Scott, another contestant, and the opportunity is finally picked up by Stacy, but you can tell how she hates herself for doing it as she accepts while on the verge of tears. It might be Honour Before Reason, but damn if it isn't incredible to watch.
In episode 9, the pressure test was to make tortellini. While Joe demonstrates the process of making and folding tortellini to the contestants, Josh is shown up in the gallery with the other safe contestants moving Christine's hands through the motions and thereby teaching her how to fold tortellini.
In Season 3 of the US version, Chef Ramsay informed the third place finisher Becky, upon her elimination and tearful statement that she would "sneak into a restaurant" to try to find some work in the food business, that she was welcome to work at any restaurant he owned, whenever she wanted. "The door's always open."
The finale of the Australian Season 4, in which terrifying pastrychef Adriano Zumbo, the bete noir of all Australian competitors, offered runner-up Julia (a pastry specialist) fulsome compliments and a paid apprenticeship after observing her in action during a dessert challenge - and after she was pipped at the post for the win by a meat-and-three-veg type who had never cooked a dessert in the competition unless forced to by the format. This sort of prize for the runner-up is not common. Julia, known for her brisk and comparatively emotionless demeanour, practically cried on-screen.
Jordan (Season Four) telling the judges that his deceased mother taught him how to cook, and revealing that the apron he's wearing belonged to her. The judges tell him that his dish is one of the best opening dishes they've ever eaten, and after he gets his apron and leaves, they can be seen sharing the rest of his food — it's just that good.
The capper has to be the shot of Jordan stopping before he gets to the door and dropping to his haunches and crying.
The marriage proposal in Season 4 Episode 1. Joe can be seen wiping away a tear in the background.
Another one from Season 4 Episode 1: the final contestant, Krissi, being surprised by her son. The judges have Krissi bring her son into the chamber so he can meet Gordon (Gordon is his hero). When Krissi gets her apron and leaves, Joe starts crying.
Gordon's face when Krissi and her son enter the chamber. He's a huge mama's boy and he loves kids, and the sheer joy on his face when he sees the pair is just adorable.
Another from Season 4: When Bri is eliminated, Gordon asks her if she has any parting words for Krissi (who had early stated that she hates Bri for being a vegetarian). Bri's comment: a sincere "Good luck, dude!"
Australian Season 4, about halfway through: Emma and Ben have misidentified types of cakes and are set to go into an elimination dessert challenge together. Every person safe from the challenge plus Emma plus the three judges saw what was coming next - Ben offers to forfeit his way out of the challenge and Masterchef itself to save Emma. He said she was there to win the competition & go as far as she could, and he was simply there to learn and he could learn elsewhere. Before the judges even rule on whether Ben can do that Beau offers to take Emma's spot in the elimination challenge. The judges knock him back, and tell Ben that even if he pulls out Emma will still be cooking in an elimination. Emma is 19 and wants to open a dessert cafe, Ben's pet cuisine is Mexican and has no idea about sweets. They continue into the challenge, Ben puts up a better dish and eliminates his 'little sister' from the competition. That Ben would have been willing to walk out for the sake of a young girl he'd known only since the beginning of the comp, makes gentle fun of her when she gets flustered and seems more upset about winning than he would have about losing speaks volumes about why he was a sentimental favourite that season.
Australian Season 3: While in the midst of a pressure test, one of the contestants, named John (who has cerebral palsy, mind you), had a very bad run, dropping cakes, burning sugar, and when the time ran out, his work was barely half-completed. So instead of serving his bad creation, he brought up a perfectly clean plate, saying he wasn't going to present his failure. Matt Preston then turned to the other two judges and Maggie Beer, guest judge, and asked them if they've ever created a dish that they've thrown away because they weren't happy with it. All of them said yes. Preston then commended John on his bravery, and Maggie rushed forward and gave him a hug.
In Masterchef Junior US episode 4, Gordon decided to help Sofia and gave her a pep talk when she was having trouble with her cake batter. Even though she got eliminated that episode, she did complete the challenge.
During the same episode's mystery box challenge, after learning that Dara was making a souffle and seeing her anxiously watching the oven, Gordon stopped by her station to join her in offering up a prayer to the "god of souffle" that her souffle would set up properly. It didn't, but the judges commended her for her ambition, commenting that they'd never seen anyone try to make a souffle for a challenge if they didn't have to.