Inside a bitsy fish store in Brooklyn, Lana Condor switched the blowtorch on. “Power!” she said brightly on a cold Friday morning, as a blade of butane flame shot from the canister. “Oh yeah.”
Ms. Condor, 21, who wields a sword as a teenage assassin in the new Syfy action series “Deadly Class,” is an enthusiastic home cook. During a break from promotional rounds, she had signed up for a sushi class at Osakana, a tiny temple devoted to locally sourced fish in the Williamsburg section of Brooklyn.
She had no idea that it would include weapons training. She clearly didn’t mind. “Holy cow!” she said as the skin on slices of golden tilefish began to sear and crackle.
Ms. Condor, who portrayed a superpowered mall rat in “X-Men: Apocalypse,” became a breakout star with the Netflix rom-com “To All the Boys I’ve Loved Before,” in which she played a high schooler with a sheaf of secret crushes.
She had arrived at Osakana with eyes bright and crimped ponytail bouncing, cuddling a fawn-colored puppy in a mauve case. Ms. Condor had fallen in love with the dog during a photo shoot at BuzzFeed and had adopted her “literally yesterday,” she said. (Ms. Condor herself is an adoptee. Born in Vietnam, she was adopted by an American couple as a baby.)
A name hadn’t yet been chosen, but Ms. Condor was leaning toward Emmy, in part because she met her boyfriend, the actor Anthony De La Torre, at the Emmys.
With the puppy happily mangling a chew toy, Ms. Condor explored the tidy store, which doubles as a restaurant and cooking school, admiring the shelves of vinegars and seasonings, the glistening slabs of amberjack and Spanish mackerel.
“This is a dreeeeam,” she said, stretching the word out. Ms. Condor is as bubbly as a case of La Croix, which is occasionally a problem on “Deadly Class.”
Based on a comic book and set at a high school for teenage killers in an ultraviolent version of 1980s San Francisco, the show has Ms. Condor playing an unflappable yakuza heiress. But Ms. Condor is extremely flappable. “The producers would be: ‘Lana, fix your face.’”
On location in Vancouver, British Columbia, where she now lives, Ms. Condor recovered from the 16-hour, combat-heavy shoots by cooking elaborate meals: spaghetti with clams, ratatouille, vegetable curry. “Seriously it’s spiritual for me, it’s meditative,” she said. “It calms me.” (Also calming: Mr. De La Torre does the dishes.)
But this was her first attempt at sushi. She traded her black spiked heels for some comfy flats and washed her dog-licked hands.
Daniel Lee, her instructor, who wore a denim apron over a polka dot shirt and had muscular forearms flecked with kitchen scars, directed her to a simple mise en place: a stone cutting service, a flashing silver knife, a plate of vegetables, a rice paddle.
“O.K., chef,” Mr. Lee said. “We’re going to brush up your knife skills a little bit.”
Sushi knives are based on katana swords, so Ms. Condor, who brandishes a katana in “Deadly Class,” had a built-in advantage. Still, she thinks Lara Jean, the finicky yogurt-drinking heroine of “To All the Boys I’ve Loved Before,” is probably a better chef than Saya from “Deadly Class.”
“Lara Jean is very into aesthetically pleasing things,” she said. “Saya would cut the fish and walk away.” Oh, and which character does Ms. Condor feel closer to? Lara Jean, again. “Because I don’t kill people,” she said.
Mr. Lee showed how to grip the knife and demonstrated how to cut the cucumber in one fluid motion, pointing the tip down and then pulling back from the shoulder. Then he had her clear the cucumber slices from the cutting board.
“A clean board is a clean life,” Mr. Lee said.
“Amen,” Ms. Condor said. “I’ve got to bring that into my life a little more.”
She sliced a daikon radish, then rolled up shiso leaves and neatly chiffonaded them.
Mr. Lee introduced her to the fish. “We got some really happy fish here,” he said. “We got some beautiful golden tilefish, we got some beautiful bigeye tuna, we got some amazing striped bass.”
Ms. Condor attacked the tuna first, a little roughly. Eventually she found a rhythm.
“It’s hypnotic,” she said.
“It’s quite Zen,” Mr. Lee said.
Ms. Condor could use a little Zen. “To All the Boys” has turned her into a star, and the lack of privacy has been tricky. “It’s scary and I don’t like it,” she said.
The other night she “snuck out” of her downtown Manhattan hotel, she said, and walked to Chinatown for some hand-pulled noodles and dumplings, only to find herself surrounded by fans. The fans were nice. “Because the movie breeds nice people,” she said. But she sometimes wishes she could maybe eat some dumplings alone.
Once the bass had been sliced and the tilefish seared, Mr. Lee spread vinegar over a bowl of rice and showed her how to aerate it. Then he talked her through several sushi preparations.
She fashioned her first piece, a glistening temari orb. Mr. Lee urged her to eat it. “The whole thing?” she asked. The whole thing.
The next piece was a pressed style, oshi-zushi. She pulled it from the mold and called to her publicist in the next room. “Look, I made this!” she said. “It’s beautiful.”
Ms. Lee had Ms. Condor fold it between crispy slices of nori and eat it like a hamburger. “This is awesome,” she said between bites.
Cheerfully, she spent the next 20 minutes making sushi for her entourage. Just when it seemed like no one could eat any more, Jonathan Garcia, the general manager of Osakana, presented her with a bowl of seafood ramen.
“Oh, it’s delicious,” she said as she slurped the noodles. “It’s like a hug.”