Vong Linna serves up a steaming bowl of Bobor sach moan, the chicken rice porridge that feeds the nation. Photograph: Pha Lina/7Days

“You can’t miss the dry shrimp,” Vong Linna, 33, says, tossing a large pinch into a steaming pot of glistening, golden chicken broth.

She is preparing Bobor sach moan – the steaming chicken rice porridge that serves as morning and evening ritual to the scores of workers who come to her stall opposite Som Nang 12 market in the Toul Kork district.

While the simplicity of bobor makes it a cheap and filling supper or breakfast, preparing the real deal at home takes more than an hour of stern, bone-sucking reduction and attention.

The result is a thick and flavoursome soup, textured with shredded chicken, slippery congealed blood and offal, if you choose, and topped with crunchy fried onion, sprouts, coriander and ginger.

Most people wouldn’t bother making it at home, Linna says. And she believes many young people with working parents and jobs of their own, wouldn’t know how.

This wealthier market – along with the increasing interest from tourists in cooking classes- was one of the reasons she decided to open her Khmer cooking school in 2010.

To make the chicken bobor for her afternoon stall crowd, Linna starts in the morning. She has two aluminium pots on the go all day, simmering away on charcoal stoves.

The porridge –although it is more of a soup than a congee- has been a specialty of hers since she was young and made it with her mother.

When I ask about her mother, Linna’s voice drops. She lost her husband, Linna’s father, and most of her family to the Khmer Rouge, she says. To keep herself and four children afloat, she worked in restaurants and sold food at roadside stalls in Kandal.

“I don’t want to forget my mum’s work,” she explains, motioning to the stoves and piles of green coriander.

After Linna married at the age of 19, her mother went to Thailand to work as a cook, sending all her earnings home to the family in Kandal.

When she returned, the two of them opened up a bobor stall for locals on Phnom Penh’s riverfront.

“There were no foreigners there then, only Khmers,” she remembers. Then, ten years ago and still in her 40s, her mother was in an accident that left her permanently disabled. She now lives in Kandal with Linna’s brother.

Meanwhile Linna, whose husband is Japanese-born, had moved to Tokyo and enrolled in culinary school, where she learnt Japanese and European cooking.

The Linna Culinary School, a gleaming kitchen space above a modern block of units, is around the corner from the modest Som Nang 12 bobor stall.

With the help of her employees, she runs between the two, serving bowls of soup in the afternoon and teaching groups how to make amok, curry and bobor from scratch, the way her mother taught her.

Bobor sach moan: 

For a large pot of bobor – the quantity seen in stalls around – Linna takes one kilo of cleaned chicken carcass and a whole chicken (pork bones can also be used), and boils it in five litres of water for 30 minutes to an hour.

She then removes the chicken and skims off the fat off the broth.

Meanwhile, she heats a generous slick of sunflower oil in a wok and adds 100 grams of chopped garlic. The fragrance mixes appealingly around the savoury flavour of the chicken.

“It’s important you choose the right rice – hard rice,” she says, measuring out a kilogram of longrain.

“People don’t like it when the rice breaks.” Which rice?, I ask. Any rice vendor will know if you tell them you want it for bobor, she says.

When the garlic is golden, she tips the rice in and stir-fries it on a medium flame until it is translucent.

Adding a little more water to the skimmed liquid, she then goes about flavouring the broth.

“For bobor, you can’t miss this,” she says and holds up a slices of yellowish, salted radish.

A few slices of that goes in, along with the papery dried shrimp, for pungency, half a dried squid, very finely sliced and the saucepan of garlicky rice.

 To contact the reporter on this story: Rosa Ellen at [email protected]