Family gatherings over the holidays are rarely stress-free. But on FX’s “The Bear,” it’s a white-knuckle experience.

Most of Season 2 of the show, which streams on Hulu, follows tortured chef Carmen “Carmy” Berzatto (Jeremy Allen White), head chef Sydney (Ayo Edebiri) and the rest of the team’s efforts to quickly transform the old school sandwich joint at the center of the show into a fine-dining restaurant. However, the anxiety-filled, stomach-turning holiday episode brings a jolt to a season that is otherwise calmer, compared to the first, by focusing on the dysfunction of the Berzatto family.

In the previous episodes, Carmy is on the brink of having everything he could want — reopening the restaurant and a budding romance with someone from his past, Claire (Molly Gordon). Episode 6, titled “Fishes,” goes back in time — nearly five years before the main events of Season 2 — to a dramatic and traumatic dinner at Carmy’s childhood home, where his family has gathered to celebrate the Feast of Seven Fishes, a traditional Italian American event held on Christmas Eve.

“And we wanted to follow up immediately with: Why wouldn’t he be prepared? Why is he in this place of maybe not being able to accept something that was so pure and honest and be afraid of somebody loving him? And diving into a Christmas flashback that we felt was representative of probably every Christmas at their house, we just thought it was a cool midpoint of the season.”

The episode is almost twice the length of the others this season, clocking in at just over an hour. And it’s stuffed with notable guest stars playing various Berzatto family members — blood-related and honorary — and friends. Jon Bernthal returns as Carmy’s late brother, Mikey; Jamie Lee Curtis is Donna Berzatto, Mikey and Carmy’s troubled mother; Bob Odenkirk is Uncle Lee; Sarah Paulson is cousin Michelle; John Mulaney is cousin Michelle’s partner, Stevie; and Gillian Jacobs is Richie’s then-wife, Tiffany. Also in attendance at the dinner are recurring charactersNatalie Berzatto (Abby Elliott), Mikey and Carmy’s sister; Uncle Jimmy (Oliver Platt); and Neil (Matty Matheson). A close-up of Jon Bernthal. His fingers are touching his mouth.

Jon Bernthal returns as Michael “Mikey” Berzatto for Episode 6.

(Chuck Hodes / FX)

“I wanted it to be distracting,” Storer said. “I wanted the viewer to be like, ‘What the f— is Bob Odenkirk doing here?’ I wanted it to really feel like when you walk into your family’s house and you are just overwhelmed by a cousin who you don’t want to talk to, an uncle you don’t want to see. You don’t even know who’s related to who, which I always feel like is the truest thing — everyone’s calling each other cousin and you don’t know what the f— is really going on, but you do know that even through all their weirdness and how dark it gets, they do kind of love each other.”

Donna in particular is a notable character, whom we meet for the first time. “We’re not sure — is she an alcoholic? Is she mentally [unwell]? Jamie did this really tricky thing with her performance, which is it to still be funny, it still gets scary, but there’s still some humanity,” Storer said.

He added that getting Curtis to play the intense matriarch of the brood was not a drawn-out process. “We sent her the script and five minutes later, we’re talking to her about it,” he said. “She knew what the fingernails were, she knew what the hair was, she built so much into this character.”

Courtney Storer, the culinary producer on the series (who is also Christopher’s sister), spent a lot of time with Curtis, walking her through her scenes in the kitchen preparing the meal. Christopher Storer said Courtney would explain to the actor “‘the branzino would go here, the sauces here’ — just getting her sort of acclimated in the kitchen.”

“Because the way we shoot our show, we do a lot of really long takes. We often do 12 pages a day in big scenes like this because I think it helps keep it really, really alive,” he said. “So it wasn’t too dissimilar from Ayo or Jeremy’s training. It was just Courtney and Jamie Lee kind of destroying this kitchen for a few days, which was really fun to watch.”

Storer said that once the casting was taken care of, the focus shifted to the episode’s other star: the food. The elaborateness of the Feast of Seven Fishes backed the theme of the episode, which was that people were trying way too hard to take care of other people. Courtney Storer and Laura Roeper, the props master, built a “little restaurant” in the house.

“Part of the reason the food is so striking is I’ve always kind of felt like home cooking is always so much more beautiful than — and I say this with zero disrespect — something that’s been plated by a three-star Michelin staff because you know that woman’s been at the stove forever and she doesn’t have the equipment to do it in,” Christopher Storer said. “I’ve been to so many Seven Fishes dinners in my life, a lot of my friends are Italian in Chicago and I grew up in an Italian family. And every time you see this ritual, you’re like, ‘No one is going to be eating all of that.’”

Storer highlighted the extraordinary performances of the actors throughout the episode, saying that he aimed to keep them acting as long as possible in the big scenes to keep the momentum propelling forward. When it came time for the big dinner table scene, there were three cameras on long lenses pivoting around the group. Natalie “Sugar” Berzatto sitting at a dining table.

Abby Elliot as Natalie “Sugar” Berzatto in the dining table scene of “Fishes.” Christopher Storer said directing it “was the most fun I’ve ever had; it just kept getting more and more out of control.”

(Chuck Hodes/FX)

The scene of the group around the dining table provided one of the episode’s most stressful moments as a hostile blowout involving Mikey, Uncle Lee and, later, Donna erupts. The tension between Mikey and Lee, seemingly over Lee’s exasperation over Mikey re-telling a story everyone’s heard, escalates quickly, with the two shouting barbs at each other and Mikey eventually slinging a fork at Lee.

“I can throw forks because this is our father’s house, my father’s house,” prompting Lee to point out that Mikey is living in the house with his mother, who he’s mooching off of financially. “You’re nothing,” Lee tells Mikey.

“At a certain point, as we started getting into it, I know Bob was like, ‘I want to f— taunt him,’ and I was like, ‘Yes!’ And then Jon would come over and be like, ‘Boss, I want to f— throw this table,’” Storer said. “As Method as it sounds, it was the most fun I’ve ever had; it just kept getting more and more out of control.”

Bernthal was originally given a weighty rubber-like fork to hurl at Odenkirk, but because it didn’t read well on camera, he ended up using a plastic one with a sound effect added in. “Jon was really trying to whip it,” Storer said. “And the thing is it’s inherently so ridiculous, him throwing a fork at someone, that it just continued to get dumber and dumber.”

Storer said in that scene, you see the different sides of the table and the partnerships.”As the scene goes on, we wanted to shrink that, and get closer and closer and closer to Bob and Jonny and the tensions growing. And because him and Bob were pushing each other, I knew we could sort of draw that out to make it even more uncomfortable and then childish and to, like, ‘OK, now this is something else and it’s getting scarier.’”

At the same time, the scene reinforces why, for example, Natalie would want to be with Pete, Storer said. “This is why Carmy could never accept the love from Claire because he thinks some crazy s— like this is going to happen. We’re trying to reinforce as much of the show as we can talk about it. Bob said this thing that was really smart, which was, ‘I don’t think this guy actually wants to fight [Mikey].’ [Mikey] is actually looking for a fight, as much as they have a weird history. So it was really great having all those things in place and start to slowly zoom in on the two of them, and just when you think it can’t get any worse, Donna comes into the picture.”

The episode took five days to shoot, with the dinner table scene taking about half a day. But the most challenging part of directing the chaotic episode was actually the food.

“It’s like, ‘Alright, we need a zoom on the timer,’” Storer says. “It’s literally, ‘Oh, can [Courtney] refire some of the tomato sauce because it was weird in the previous take?’ The thing we’ve learned on this show is that food is always just the f—. We tried to just shoot a bunch of the show, and then get the actors out, and then go shoot close up of the food. You look at a scene, like what happens at the end of this episode, and it looks really complicated. But the truth is, we got some of the best actors in the world.”

‘The Bear’

Where: Hulu When: Anytime Rating: TV-MA (may be unsuitable for children younger than 17)