Hee Sook Lee’s recipe for soondubu, a steaming bowl of soft tofu in a spicy, bright-red beef bone broth, was so secret, she wouldn’t even share it with her husband.
While he and her young sons slept, Ms. Lee, who owned a restaurant in Los Angeles, spent many long nights in the kitchen experimenting with spices until the dish was just right: the tofu just silky enough that it melted not on the spoon but on the tongue; the broth adding just the right kick of gochugaru, or Korean red chili pepper.
Soon it was time to introduce the soup at her restaurant, and when she did, she could not have foreseen its impact: It would help her establishment grow into a national chain while the dish itself would become something of an American cultural phenomenon.
Ms. Lee, the founder of the BCD Tofu House chain, died on July 18 in a hospital in Los Angeles. She was 61. Her eldest son, Dr. Eddie Lee, said the cause was ovarian cancer. Dr. Lee, who was an assistant professor at the Keck School of Medicine of the University of Southern California, helped his mother manage the business in recent years as its interim chief executive.
Beginning in 1996 with one restaurant in Los Angeles, on Vermont Avenue in Koreatown, the BCD Tofu House chain, famous for drawing line-out-the-door crowds, now has 13 restaurants in 12 cities across the United States, including New York. Some are open 24 hours a day, for those who work odd hours or for young people hungry after a night on the town and craving Ms. Lee’s secret soondubu or other Korean dishes on the menu.
“The secret is in the seasoning,” Dr. Lee said of the soup in a phone interview. “That’s all I can say, or it won’t be a secret anymore.”
Hee Sook Hong was born in Seoul, South Korea, on June 24, 1959, one of four daughters of Young Pyo Hong, a teacher, and Chun Ja Park, a homemaker.
When Hee Sook was in middle school, a stroke left her father paralyzed. To support the family, her mother began washing dishes in restaurants and selling items at flea markets. After high school, Hee Sook began working, too, to bring in extra income. She was the second-oldest daughter but the most responsible, leading her mother to tell her, “You are the son of the family now,” Dr. Lee said.
In 1983 she married Tae Ro Lee, a lawyer who had become a restaurateur. They moved to Los Angeles in 1989 so that her sons could learn English and gain better educational opportunities.
Once there, Ms. Lee began looking for a way to earn a living. She enrolled in the graphic design program at Santa Monica College and graduated in 1994.
The idea to open a restaurant came to her one Sunday in the mid-1990s while sitting with her family in the pews of Berendo Street Baptist Church. During the service, her sons’ stomachs began to growl, and they begged to go to the soondubu restaurant across the street after church.
“My brothers and I would love eating there,” Dr. Lee said. “That got her thinking that tofu soup really would be something unique that she could focus on.”
She decided to name the restaurant BCD Tofu House, short for Buk Chang Dong, a neighborhood in Seoul, where her father’s aunt ran a tofu restaurant. Ms. Lee became fiercely dedicated to the business, waking up in the early morning hours to handpick produce at the wholesale market downtown.
“Anything she put out on a table, it had to be perfect,” said Dr. Lee, “whether it was the temperature of the rice, the color of the kimchi, the saltiness of the tofu seasoning.”
And people came. “Today, tourists from South Korea arrive by the busload at BCD Tofu House and snap photos,” The Los Angeles Times wrote in 2008. “Visiting dignitaries, sports stars and actors frequently dine at the restaurant. Even though the restaurant is open around the clock, there is almost always a wait.”
During the coronavirus pandemic, Ms. Lee continued to provide health benefits to laid-off workers and additional wages to those who stayed to help with takeout orders. And knowing that during a health crisis people might need hot soup more than ever, Ms. Lee kept the BCD Tofu House outlet on Wilshire Boulevard in Los Angeles open 24 hours a day.
In addition to Dr. Lee, she is survived by two other sons; her husband; and her sisters, Myung Hee Hong, Sung Hee Hong and Sung Im Lee.