Monday's full moon signals the end of prahok season for the year. The season brings thousands to the fishing villages north of Phnom Penh to buy fish and prepare the distinctive national dish. The first quarter of the moon in January and February fills the Tonle Sap with migrating riel fish that will soon be fermented to make the intensely flavored fish paste.

Boisterously described as both fabulous and foul, Cambodia's famous

fermented fish paste defines the country nearly as much as Angkor Wat or the Tonle

Sap, and the passion it inspires in its aficionados borders on religious.

On a recent morning at a wooden stilt village on the west bank of the Tonle Sap,

three generations of an ethnic Vietnamese family squatted around a pile of gleaming

silver fish and methodically chopped off their heads.

Ngieng Thila, 60, had been hired with her daughter and young grandson to prepare

the fresh catch of tiny fish called riel. The two women worked quickly, expertly

severing the heads with a cleaver on a round wooden board. Flies circled excitedly

as the boy scooped up piles of the chopped fish from the muddy ground and tipped

them into a big basket ready to be cleaned.

The family was preparing the most malodorous of Cambodian delicacies-one that Cambodians

would defend at any table in the world. It is mushy and gray and piquant. It has

an overpowering vinegary odor that is never forgotten. Foreigners impolitely call

it "fish cheese," but actually it is a fermented fish paste loaded with

salt. It's called prahok, and February is the month to make it.

The family's employer, Choup Mom, 42, stood by and watched their progress. Mom, from

a nearby village, said she spent about 200,000 riel getting some 160 kg of prahok

made each year.

"I make prahok every year because I eat prahok every day," Mom said. "I

not only feed my family, but my relatives and the monks."

Mom said she preferred to make prahok herself rather than buy it because she could

ensure it was fermented long enough to become "really tasty."

Once the heads are removed the fish are washed and placed in baskets for one day-until

they swell and start to smell. Salt is added next, with about one part salt to three

parts fish. After another two days the mixture is compressed inside clay pots and

left to ferment for about three months. Only then is the prahok considered "chngain"-delicious

enough to eat.

The moon's first quarter leads schools of the silver-colored fish up the Tonle Sap

each January and February. Prahok season takes place during the eight days from the

start of the half moon until the full moon. During that time the provinces that flank

the Tonle Sap-Kampong Chhnang, Siem Reap, Kampong Thom, Battambang and Pursat-come

alive with the business of catching fish and processing it into paste.

During prahok season the rice fields of the riverside provinces are full of drying

fish, according to Seng Sophea, who is a homegrown prahok expert from the fish-focused

province of Kampong Chhnang.

"They're not rice fields, they're fish fields," she laughed.

"On the way to my home town you smell prahok everywhere. You close the car window

very tight, but you can still smell it."

The prahok recipe is centuries old, she said, and grew out of the need to preserve

fish during the months when the staple food was less plentiful.

The biggest hotspots for prahok making are the fishing villages ten or so kilometers

north of Phnom Penh, Sophea said. People flock there each year to replenish their

prahok stocks. A little prahok goes into almost every Khmer dish, Sophea said, so

even the landlocked needed to have some in store.

The stilt village of Preak Phnoa, where Ngieng Thila sat chopping heads, is one of

the top destinations during the season. This year most rural Cambodians had arrived

in January, the villagers said, and took their fill of this season's unusually large

catch. Ordinarily the muddy riverside would be crammed with people chopping fish

and stomping on it in baskets, but this morning only a few locals were preparing

the paste. Still, the telltale smell wafted from the market stalls that lined the

road from Phnom Penh. A fruit stall had prahok for sale in small bundles swinging

above green vegetables, tomatoes and pineapples. A palm-sized bundle of fish cost

200 riel. The shopkeeper said she typically sold 15 to 30 bags each day.

Prahok makers traditionally prepare the paste by vigorously stomping their feet in

a large basket of fish. But motorized machines for removing scales, heads and fat

are becoming more popular.

Prahok is rarely eaten raw. It is usually steamed or fried with minced meat and eggs

and served with vegetables, or cooked in soup, according to skilled cook Soung Srey

Oun. She agreed that some foreigners did not like the taste of prahok, but said that

as with any delicacy, it could be magic in the hands of the right cook. And Oun should

know, having once prepared prahok for a wedding feast attended by Prime Minister

Hun Sen.

Prahok should be used sparingly because of its strong taste, Oun said, and it should

be combined with other powerful flavors, like garlic, lime and chili.

Oun went into raptures when asked to describe the flavor for those who had never

tried it.

"Good, delicious, sweet, and- you just feel you want to eat more and more,"

she said.

"When you have prahok with any other dishes, you just want to eat the prahok.

You don't even want to try the other dishes."