Meet the London Chef Serving Cambodian Dishes That Escaped a Genocide

For many in Europe and North America, April 1 is a day for getting away with cellophaning toilet bowls and greasing doorknobs. But in Cambodia, the date marks something much more sombre.

On that day in 1975, the country's then-President Lon Nol was forced to flee the country, as an eight-year civil war against the Khmer Rouge entered its final phase. Little more than a fortnight later, the communist guerrillas marched into the capital Phnom Penh and one of history's most infamous genocides began.

Around a quarter of Cambodia's 8 million inhabitants died over the following four years, the vast majority executed as part of the Khmer Rouge's radical attempt to impose an agrarian socialist society. A generation of artists and intellectuals was butchered, and cultural traditions were wiped out.

But in a tranquil corner of North London, just a few hundred meters from the bustle of Camden Town, one Cambodian man has preserved some pieces of culinary heritage largely lost to his homeland more than 40 years ago.

Thomas Tan left Cambodia as a teenager in 1969, heading to London to study English. As the son of a wealthy family, Tan was destined to return home and rub shoulders with the elite, just as he had grown up watching his father do. But history conspired against him, and his trip to the UK turned into permanent residency. Twenty years after arriving in London, he opened Lemongrass Restaurant, which today remains London's only dedicated Cambodian restaurant, and one of only three in the UK.

As a child, Tan says his love for Cambodian cuisine was bred into him by his food-obsessed father, who first encouraged him to start cooking when he was just six years old. He had his own fully fitted kitchen before he reached the age of ten, and every day he would prepare his father's favourite dish: steak marinated in a lime, salt, and pepper sauce, known as lok lak.

"The fridge in my kitchen was always full of steak," says Tan. "My father was very particular about how it should be cooked and if you got it wrong, you had to do it again and again."

In Cambodia today, lok lak is a mainstay of restaurant menus, usually consisting of beef served in pepper sauce on a bed of raw onion, tomato, and lettuce. But Tan says the plate of cheap cuts fried in oyster sauce served in Cambodia now is a shadow of what it used to be. He sees it as the result of Chinese influence on modern Cambodian cooking.

According to Tan, real lok lak requires top quality steak fried in butter—a tradition that stems from Cambodia's French colonial past. The chef also has a special recipe for the classic marinade, which he brought with him to the UK in the 1960s.

"But that's a secret," he says. "The only one I have taught it to is my son."

The result is a plate of fillet steak so tender it might melt if you didn't chew it, slathered in a sauce that leaves you wondering if the restaurant's low-key vibe makes it relaxed enough for you to lick your plate clean. Having recently decided to restrict my meat consumption to two meals per week, I was glad this was one of them.

Lok lak may sound like an opulent dinner choice, but the prices at Lemongrass are more than reasonable. Ordering the dish with a side of rice (the fresh ginger egg-fried rice is definitely worth dropping the extra 70p for) comes in cheaper than a forgettable pub burger from down the street.

While frying steak in butter is not the only pre-Khmer Rouge element of Tan's cooking, it is one of the few he will speak about openly.

"All of my recipes I brought with me, I just can't tell you my secrets," he says with a smile, though if you follow him on his 6 AM daily run to Soho's Asian markets, you might be able to uncover some clues.

Beyond his guarded recipes, Tan is also obsessed with freshness—something you can taste in every dish he insists on me trying. The Indo-Chine king prawns surge with lime and chili, while juicy chunks of mango burst in the heat of the crispy spring chili chicken.

One dish Tan isn't coy about discussing—which he says used to be common in Cambodia but is not widely eaten today—is his lemon butter mushrooms starter. Combining the citrus and pepper widely found in Cambodian cooking with the butter and garlic more commonly associated with French cuisine, Tan says he has customers visit from from across the country just to try them. And I can say wholeheartedly, I have never known mushrooms to taste so good.

"This is the first thing I ate here 25 years ago," says one diner, after polishing off a plate of the fungus. "And I have it every time."