CHICAGO — Claudia Dietrich and Ross Lloyd boarded a bus bound for the hottest tourist spot in the River North neighborhood. While their guide rattled off Chicago trivia, the couple snapped photos from every angle — even the alley. They weren’t deterred by the winding line out the front door.

“This is something that brought us to Chicago; there’s no doubt about that,” said Dietrich, a 72-year-old Milwaukee resident.

Their destination? Mr. Beef, the no-frills sandwich joint featured on Hulu’s smash hit, “The Bear.” It’s the first stop on their guided food tour inspired by the series.

A traditional Chicago sandwich shop may seem like an unconventional excursion. But since “The Bear” debuted, tourists have flocked in droves to Mr. Beef, which opened in River North in 1963. Ahead of Season 3’s release, its cult following is surging with renewed enthusiasm.

Just ask one of the food tour’s 30 patrons, who were bused to six restaurants in River North, the West Loop and Logan Square last Friday afternoon. Many of the restaurants on the tour served as filming locations for the series.

“I just think the show is so authentic,” Dietrich said after sampling an Italian beef sandwich with giardiniera. “And you can practically taste the food when you watch.”

“The Bear” follows Carmy, a young gourmet chef who seeks to transform his late brother’s sandwich shop into a fine dining establishment. There, he clashes with the diverse, unpretentious staff in often anxiety-inducing kitchen scenes — most of which were shot at Mr. Beef. When reached by phone to ask how business was going ahead of the premier, a manager at Mr. Beef told the Tribune that he didn’t have time to comment because of the line of customers out the door.

The series has been lauded for its unflinching portrayals of the restaurant industry and lovable characters, winning six Primetime Emmys this year including best comedy series.

Chicago Food & City Tours began the themed excursions in November after months of requests from guests. The tour is modeled after Season 2, Episode 3, when sous chef Sydney treks across the city to try different restaurants — not unlike a food tour, said Hannah Gleeson, the company’s director of operations.

“It just became really evident that there was a demand, and people wanted it,” Gleeson said. “Our team had been longtime fans of ‘The Bear.’ So, why not try to give people that same experience?”

As guide Casey Ross led the group, he sported a blue apron over a white T-shirt — the uniform at the fictional Original Beef of Chicagoland. He also held a tomato can tip jar, another tribute to the series. The tour’s charter bus was brimming with excitement.

“We only have one hard and fast rule,” Ross, 41, told the group. “If I ask a question, the answer is going to be —”

“Yes, chef,” they responded.

“Did you guys practice outside?” Ross quipped.

Ross, like most of the guests, is an avid fan of “The Bear.” He moved to Chicago over eight years ago from Kansas. The actor even auditioned for a small role in the upcoming season — but he didn’t get the part.

“I can’t wait to see the episode and see (who) they hired,” he said. “I’m going to be so mad if it’s another bearded redhead.”

After Mr. Beef, guests sampled pot stickers from Time Out Market, pepperoni pizza at Pizza Lobo, doughnuts at Roeser’s Bakery, hot fudge sundaes at Margie’s Candies and drinks at the Green Door Tavern.

Selecting the stops was a lengthy process, according to Gleeson. Many of the restaurants featured on the show were Michelin-starred — Elske, Ever and Kasama, for example. Others, such as the tiny Lao Peng You in Ukrainian Village, couldn’t accommodate large groups.

The three-hour tour remains one of the company’s most popular and is frequently sold out on the Fridays and Saturdays it runs. Usually, the crowd is an equal mix of locals and tourists, and private tours are also available, Gleeson added.

“‘The Bear’ does such an amazing job of highlighting Chicago’s diverse food scene,” Gleeson said. “And it’s so much more fun to do something like this than just walk up to Mr. Beef.”

Outside of Roeser’s in Humboldt Park, sisters Joan and Cora Lanman mulled over possible plot lines for the show’s upcoming season. While posing for photos, they exchanged theories: Were co-stars Jeremy Allen White and Ayo Edebiri dating in real life? Would their characters date on the show? And what about Carmy’s girlfriend, Claire, whom he left in the last episode?

“I just think Season 2 is, like, one of the best seasons of television of all time,” said Joan, 22. She’s seen the show three times through. “I think the writing is so real, it doesn’t feel like a TV show.”

The sisters, from Atlanta, were visiting their parents in Chicago. The favorite part of “The Bear” is that it creates a space for each character’s personal growth, they said. Take Richie, Carmy’s disgruntled family friend, who discovers his passion for hospitality during a feel-good montage to Taylor Swift’s “Love Story.”

“I love Richie,” Cora, 19, said. “And I love that Taylor Swift song. That episode makes me so happy.”

Then there’s 72-year-old Diane Thomas, who fell in love with “The Bear” because of its depiction of complex kitchen dynamics, along with the pitfalls of a family business. As a teen, Thomas worked at her own family’s sandwich spot in Michigan, Stage Delicatessen. Her brother still owns the establishment.

“It’s all of our cousins and nieces and nephews, all working together,” Thomas said. “I think ‘The Bear’ shows the real chaos that happens in the kitchen.”

Beside her sat 68-year-old Jim Walsh, eating pot stickers at Time Out Market. The friends call each other “playmates” — Walsh was recently widowed, while Thomas’ husband prefers to spend his days inside. They frequently attend guided tours across the city.

“I just love things like this,” Thomas said.

Farther down the table, other guests chatted about the show. Here, “The Bear” takes precedence above all other forms of small talk.

“I actually just saw Jeremy Allen White on a late-night show last night,” said Tiffany Harding, in between bites of food. “One of the Jimmys hosted.”

“Of course, we had to rewatch it in anticipation of Season 3 coming out,” Terri Henry said. “We’re ready.”

After three rounds of “The Bear” trivia, the bus finally pulled up to the storied Green Door Tavern. Each guest selected either an old-fashioned or soda. Ross was still smiling as he stood by the wooden bar three-and-a-half hours later.

“I love having people to talk to, and I love sharing information and telling a good story,” Ross said. “I’m an actor, and so I crave an audience, I guess.”

Ross said he, like many others, was nervous about the crew’s new restaurant and the fate of the characters he’d grown so fond of. But excitement trumped the stress.

“All of these characters are becoming three-dimensional, and I can’t wait to see more of that,” he said. “That, and the lovingly crafted shots of Chicago. It’s a love letter to the city.”