With its subtle flavour and compact packaging, kralan seems like a simple but satisfying snack, but making it is a laborious process for those who stake their livelihoods on it.

The snack consists of sticky rice cooked in coconut milk, with black-eyed peas or beans stuffed and cooked inside a bamboo tube.

Kratie province is most famous for kralan but it’s along a stretch of road that straddles Sotr Nikum and Prasat Brakong districts along National Road 6 where vendors are most visible. That’s where Phoey Phorn, 37, operates the largest stand, which he has run with his wife, Phai Bopha, for the past decade.

“My wife’s family had sold kralan far before I married her and carried on the business,” Phorn said. “Many people are buying, but I had not expected it to be such exhausting business.”

Every morning, Phorn gets up at 5 to prepare the fire, while his wife prepares the bamboo tubes. After two hours, the couple stuffs the tubes with rice, flavoured with salt, sugar and milk, and with beans.The top is stopped with hay and the tubes are then roasted over the fire. At that point, Bopha shaves off pieces of the bamboo to make the tube thinner before it is again placed over another fire.

“We have to do all the work on the street so that we can sell our kralan at the same time [as preparing],” he says.

In the morning, on the well-known “kralan road”, there is a thick haze of smoke. Although all of the vendors are selling the same snack, most have come up with their own unique flavours by calibrating the recipes. For example, one vendor puts pieces of mango in his kralan, while another adds slices of jackfruit. The prices are all the same: 3,000 riel ($0.75) for a large tube and 2,000 riel for the smaller ones.

Although many travellers on the highway stop and buy kralan there, many vendors worry they won’t sell out. The snack keeps for only one or two days after it is cooked, and the rice hardens quickly.

Pich Sreyleak, another vendor, says only on holidays like Khmer or Chinese New Year does she make big batches of kralan, selling much fewer on a normal day. Still, it’s a profitable business for her family.

“On a good day, I could sell up to 400 pieces of kralan,” she says. “The income helps us live comfortably, adding to what we get from farming.”

Nonetheless, the work is too hard for Sreyleak to want to pass it on to her children, which is why the snack is a way for her to give them an education.

Despite being part of the diet in other parts of Southeast Asia, such as Thailand and Laos, historian Dr Michel Tranet claims that kralan originated in Cambodia. It was first invented by Mon Khmer, an umbrella term for the earliest known ethnic groups in the country.

“We cannot confirm when kralan was first made,” Tranet says. “But, archaeological evidence proves that the people from Mon Khmer tribes cooked rice into the bamboo,and it was also served as soldiers’ food during the Angkorian era because it was easy to carry.”

Tranet speculates that the kralan in Thailand, known there as khao lam, is influenced by Khmer people in Surin, a former territory of the powerful Khmer Empire.

Ey Nat, a 50-year-old farmer from Kandal province who always stops to buy kralan at the rest stop, sees the snack as a symbol of the hard work and patience of Cambodians.

“I see them working so hard, and the result is a simple but delicious snack,” she said. “I want all the foreigners who visit Cambodia to try it.”