One day last week, a vase spilling over with white lilies and roses arrived in Kristen Kish’s dressing room in Milwaukee, where “Top Chef” is shooting its 21st season.Padma Lakshmi, the model and author who became a household name during the 17 years she hosted the cooking-competition show, had sent them, along with a note: “Break a leg. I’m so proud of you kiddo!”For Ms. Kish, who was so nervous her first day on the set as Ms. Lakshmi’s replacement that she thought she might throw up, the flowers were a balm.“I know my job is to simply be me,” Ms. Kish said, “but I feel like I am not going to be impressive enough to hold my own space and follow in Padma’s footsteps.”Truth is, the aging “Top Chef” franchise, which has had its share of stumbles in an increasingly crowded constellation of food shows, needs her as much as she needs it. At 39, Ms. Kish represents a third wave of chef celebrity, far removed from pioneers like Emeril Lagasse and Bobby Flay, and the generation of tattooed, mostly white kitchen bros who followed.Ms. Kish is a gay Korean adoptee and a proud product of the Midwest. She hits the notes sung by culinary stars before her: She co-wrote a cookbook, opened a restaurant and makes much of her living on camera, a skill she polished on several other shows before landing the “Top Chef” job in July. On social media, she toggles seamlessly between charming brand promotions, food tips and sincere declarations — about love, self-care and even self-doubt — that can border on oversharing.Under all her casual confidence, she says, is a foundation of crushing insecurity.Ms. Kish has been on “Top Chef” as a contestant and judge, and is comfortable on the set in Milwaukee.Lyndon French for The New York Times“I have severe social anxiety and I’m on television, which is wild,” she said. “I know I’m a walking contradiction.”That’s hard to buy when you see her stride onto the set with the command of a model (which she once was). The show’s stylist selected heeled boots and wide pants for her tall, lean body as a way to project authority. She broke into a goofy dance one moment, then hit her mark perfectly the next. The first time she uttered, “Please pack your knives and go” — the chilling phrase Ms. Lakshmi delivered when a contestant was eliminated — the crew applauded.“Kristen is a megawatt,” said Dana Cowin, the former editor in chief of Food & Wine and a “Top Chef” judge for seven seasons. She recently watched Ms. Kish confess her personal fears as she demonstrated how to make Korean-style corn dogs for a rapt audience at the Food & Wine Classic in Aspen, Colo. “She was just so vulnerable and open.”If Ms. Kish had a brand, it might be wrapped in millennial pink and laced with the ideals of a generation that values earnestness, diversity and being nice.“She’s been on a huge journey defining how we can be a chef in the post-celebrity-chef era and how we can think about our global community in a bigger way,” said her friend Gregory Gourdet, the Portland, Ore., chef who was both a judge on the show and a finalist.The Heir ApparentIt all started when Ms. Kish won “Top Chef” in 2013.“She is completely a creature of the franchise,” said Francis Lam, a frequent guest host and the vice president and editor in chief of Clarkson Potter, which published “Kristen Kish Cooking: Recipes and Techniques” in 2017. “On some level she can be a little bit of a cipher. People can put a lot on her based on their assumptions.”When Ms. Lakshmi announced that she would not renew her contract as the show’s host and executive producer, Ms. Kish was the clear choice, said Casey Kriley, a chief executive of Magical Elves, the unscripted-production company that created the show. Executives at NBCUniversal, which owns Bravo, the network it airs on, never interviewed anyone else, said Ryan Flynn, a senior vice president.“She checks all the boxes,” he said.Ms. Kish battled Brooke Williamson in Seattle to win Season 10 of “Top Chef” in 2013.David Moir/BravoMs. Kish got word that “Top Chef” wanted her while flying back to the East Coast with her wife, Bianca Dusic, after doing promotional work for a hotel in Thailand.“I was shocked,” she said. “I really wasn’t pushing for this because I never thought it was actually a possibility.”Ms. Lakshmi was the first person she called. “I hope I’ve been a sounding board for her over the last decade,” Ms. Lakshmi wrote in an email. “I’ve made it my mission to mentor young women like her because I didn’t have that coming up.”Ms. Lakshmi, a victim of sexual assault, often spoke out about sexual harassment in the restaurant industry, including accusations against a “Top Chef” winner, and pushed to make the show less Eurocentric.Ms. Kish said that although she will have no problem being blunt if she needs to, she intends to focus on the work, not the politics.“TV is populated by people who love to hear their own voice,” said Hugh Acheson, a chef who made his name with restaurants in Georgia and was a judge on the show for six seasons. “And that isn’t Kristen at all.”Tom Colicchio, the chef who serves as the show’s head judge, said he was excited to have someone new in the mix, especially an experienced chef. “She knows what she’s doing,” he said.Gail Simmons, the show’s other judge and a close friend of Ms. Kish, didn’t think she needed much advice: “The only concern I had was her own self-doubt.”Gail Simmons and Tom Colicchio, Ms. Kish’s new co-workers on “Top Chef,” said they she didn’t need much advice before shooting Season 21.Lyndon French for The New York TimesUnder ControlA precise and focused cook with French and Italian influences, Ms. Kish has long relied on organization to counter her anxiety. Growing up in a suburb of Grand Rapids, Mich., she kept a whiteboard in her room to keep track of her schoolwork, piano lessons and sports. Her older brother, Jonathan, an automotive engineer, gave her a cordless vacuum as a housewarming present when she recently moved to Connecticut with the Australian-born Ms. Dusic. She uses it every day she’s home.Ms. Kish is much looser about what she eats and wears. She prefers hoodies and a ball cap turned backward. Her favorite cosmetic is Carmex. She’d just as soon eat chicken tenders, sour candy and squares of presliced Colby-Jack cheese on a saltine.The Hamburger Helper that brought her joy as a child inspired a pasta dish of curly edged mafaldine tossed with mushrooms and pearl onions that is popular at her Austin restaurant, Arlo Grey.This baffles her mother, Judy Kish. “I truly did not use Hamburger Helper very often,” she said during a recent family interview on Zoom. “I really don’t understand why it’s so vivid in her memory, to tell you the truth.”The elder Ms. Kish was a high school teacher, and her husband, Michael, was an engineer at a company that made corrugated cardboard boxes. In 1984, the couple adopted the four-month-old Kristen, who had been abandoned shortly after birth at a clinic outside Seoul.They strove to keep her connected to her birth country, making sure she tasted kimchi, introducing her to a Korean exchange student and reading her “The Korean Cinderella” by Shirley Climo. (Ms. Kish had the story spray-painted on the restroom walls of her restaurant. Speakers softly play a recording of a woman reading it in Korean.)A young Ms. Kish giving her mother, Judy, a ride on a tractor. Courtesy of Clarkson PotterFor a long time, Ms. Kish tried not to think about her Korean roots. “I put it aside because I was scared that I was going to find out something that I didn’t want to find out about where I actually came from,” she said.Still, in her 20s, she had her Korean name and adoption case number inked on her wrist — the first of many tattoos marking important moments in her life.After she won “Top Chef,” she vowed to use some of the $125,000 prize money to visit South Korea, but couldn’t go through with it. Nine years later, Netflix sent her to Seoul on a five-day promotional trip tied to her work as a host on “Iron Chef: Quest for an Iron Legend.” She didn’t search out orphanages, as some adoptees do. Instead, she focused on learning about the food.Can someone who didn’t grow up in a Korean family legitimately cook the cuisine? It’s a question she grapples with.“I’m trying to own that side of me so it doesn’t feel like I’m appropriating a culture that doesn’t belong to me,” she said. “I clearly can have a point of view about Korean American food. There is a connection. I’m allowed to explore it. But for a long time I felt guilty about it.”An Education in FameDespite her shyness as a child, she had a lot of friends. By high school she was firmly ensconced with the preps.“We had Abercrombie clothes, and I had purple contacts,” she said. “I was trying to be everything except me. I wanted to hide.”Especially, she said, her budding attraction to women.Her grades weren’t good enough to get into Michigan State University, where her brother and both her parents graduated. She spent a year at Grand Valley State University, but didn’t go back. Her parents, who said she always had a creative streak with food, sent her to Chicago to attend Le Cordon Bleu College of Culinary Arts. She loved it and graduated, but also discovered cocaine and the bars.“A lot of it was trying to mask and self-medicate my social anxiety and my sexuality,” she said. Ms. Kish convinced herself that being successful couldn’t include being gay.Ms. Kish brings her longtime hairstylist to the set, and likes to have a candle and candy in her dressing room. Lyndon French for The New York TimesShe kept partying, turning down jobs she thought were beneath her. Finally, her parents stopped paying for her nice apartment. She moved back home, depressed and defeated.They gave her one more chance. They knew of a room for rent in Boston, and offered to help pay for it if she found a job within three weeks.She did, cooking in a series of kitchens that led to a job at Stir, a cookbook store and demonstration kitchen owned by the chef and restaurateur Barbara Lynch. Ms. Lynch became a mentor, passing her name to producers who had called looking for new “Top Chef” contestants.Ms. Lynch wrote a letter that Ms. Kish had in her back pocket when she won. “So very proud of you,” it read. “Breathe and most of all enjoy the experience!!”Ms. Kish doesn’t have much to say about recent reports that Ms. Lynch verbally and physically harassed workers at her restaurants.“I had been removed from her company for 10 years, so I don’t know,” Ms. Kish said. “What I do know is that if she never said, ‘Kristen, you can win Top Chef,’ none of this would be happening. And that’s a fact.”Over a cheeseburger at Gramercy Tavern in Manhattan last month, Ms. Kish pondered how to navigate her fast-rising fame. She guards the name of the town where she lives, and is careful what she says when she’s out somewhere, because people eavesdrop. She is trying to get better at responding to the strangers who approach her in places like the supermarket.Bianca Dusic, Ms. Kish’s wife, often travels with her to jobs, and is close with Ms. Kish’s family.Lyndon French for The New York Times“When I get insecure and uncomfortable and socially anxious, I kind of become, for lack of a better term, a bitch,” Ms. Kish said. Ms. Dusic prompts her to snap out of it with a code phrase: “Nasty Nancy’s here.”The two met when Ms. Dusic was the corporate executive assigned to help Ms. Kish open her Austin restaurant in the LINE Hotel in 2018. After six months of intense work side by side, they shared a high-five that lasted a little longer than they expected.They were married in their backyard in April 2021. As with their engagement, Ms. Kish announced it on Instagram.Ms. Dusic, 44, left the restaurant industry when the stress of working during the Covid shutdowns and grief over her father’s death from cancer made her sick. Now she is a “mind-set and transformation coach” who offers breath work and other therapies, which she uses to help Ms. Kish. She also has persuaded Ms. Kish to stop ordering so much takeout.Ms. Dusic frequently accompanies Ms. Kish when she works. At home, they putter in the garden, drink tea and are in bed by 10 p.m. It’s all about managing a life that just keeps getting bigger.“This was never the plan,” Ms. Kish said. “The plan would have been for me to just work in a little restaurant, making ends meet, doing my life and just keep trucking along.”Follow New York Times Cooking on Instagram, Facebook, YouTube, TikTok and Pinterest. Get regular updates from New York Times Cooking, with recipe suggestions, cooking tips and shopping advice. More