SELF-RESPECTING foodies will know that the best part of a mooncake isn't its sweet lotus paste filling but the salted duck egg yolk at its core.
Now, imagine that sinful yellow blob beaten to a mush, smeared generously over prawn, crab or lobster meat, then sauteed in a hot wok.
The sumptuous concoction is likely to send your tastebuds into a tizzy - or have you worrying about going into instant cardiac arrest.
Whatever your inclination, the humble salted egg yolk - whipped into a paste form - seems to be the ingredient du jour in the Chinese restaurant scene.
At The Seafood International Market & Restaurant in the newly opened Playground@Big Splash in the East Coast, group executive chef Pung Lu Tin introduced his pumpkin with salted egg yolk dish when the restaurant re-opened after renovations last month.
He wanted to bring out the flavour of the vegetable and decided that a sauce with a salted egg yolk base would do the trick.
'Pumpkin has a unique flavour. It has the sweetness of sweet potato and crunchiness of yam combined. Somehow, the salted egg yolk helps to enhance these flavours,' he says.
The unconventional dish is steadily winning over diners, with at least 10 orders being made for it every day, he adds. Also on his menu are prawns and crab with salted egg yolk.
Indeed, at least 10 eateries, from zhi char places such as Boon Tong Kee to haute Chinese cuisine establishments such as Lei Garden, carry variations of salted egg yolk creations, either as part of their a la carte menus or upon special request (see other story).
The origins of this food phenomenon, which came about over the past five years, are hazy. But it is possible that chefs here got their inspiration from their counterparts across the Causeway.
Tung Lok group's corporate chef Sam Leong says: 'When I started working 20 years ago in Johor, restaurants there were already serving prawns and curry crab with salted egg yolk.'
Makansutra food consultancy founder and food critic K. F. Seetoh, too, remembers visiting a restaurant in Cheulai, just outside Kuala Lumpur, that was widely regarded as a pioneer of the crab and salted egg yolk dish.
Though he does not recall its name, he says: 'This was a small air-conditioned zhi char place that was filled with people every night.'
For the uninitiated, salted eggs are a staple Chinese preserved food product made by soaking duck eggs in brine or covering them with salted charcoal. Though the egg whites are saltier, the yolks are also valued for their texture.
Restaurateurs and chefs LifeStyle spoke to say their supply of salted eggs typically comes from countries such as China, Thailand and Malaysia.
In general, to transform the yolks into a coating, kitchen staff steam them first and then add butter or evaporated milk. This is then best paired with seafood or vegetables as such foods do not have strong flavours.
At Lei Garden in Chijmes, the yolks have to be hand-picked by its chefs, the restaurant's executive manager Angie Chew says.
'Not all the yolks have a nice texture. Some may be lumpy or not as fragrant as we want them to be, so we use them for other purposes.'
The restaurant has been serving salted egg yolk dishes since 2000, with one of its top sellers being the baked live lobster with salted egg yolk. 'Out of the 30 tables that we serve every night at dinner, almost half will order the lobster,' Mrs Chew says.
Apart from lending a touch of salty zing to, say, an otherwise run-of-the-mill stir-fried crab dish, salted egg yolk has also become a chef's pet ingredient because of its auspicious golden colour.
'In Cantonese, we call it 'kum heong' (literally translated as 'golden fragrance'),' says Ms Veronica Tan, co-owner of Peach Garden restaurant, which is famous for its crab claw with salted egg yolk.
So with such concoctions becoming more commonplace, how does one tell the good from the bad?
'The salted egg yolk coating should be light,' says Mr Seetoh. 'It should also not be oily or clumpy.'
But if you're thinking of rushing out for a four-course meal of salted egg yolk dishes, here's one word to ponder: cholesterol.
According to the Health Promotion Board, one salted duck egg yolk weighing about 70g contains 359mg of cholesterol.
As an indication of how much cholesterol you'll be consuming, Lei Garden's baked lobster is made with about two egg yolks while Seafood International's pumpkin dish has two to three yolks.
Ms Anna Jacob, a nutritionist and dietitian, says that healthy diet recommendations suggest that cholesterol intake should be less than 300mg a day.
'So, just one salted egg yolk will be above the recommendation,' she says. 'If an individual eats a lot of salted egg yolk and does it regularly, there may be a greater risk of elevating blood cholesterol level. This, in turn, may increase the risk of heart disease.'
The figures may scare off health-conscious diners but it seems like some restaurants may have found creative ways to skirt the issue.
At Tung Lok's My Humble House at the Esplanade, a prawn and salted egg yolk dish is served seasonally - depending on menu changes - or upon request.
Mr Leong says: 'We try not to use the words 'salted egg yolk' on the menu because some customers, especially the elderly ones, will say 'wah, high cholesterol'. We may call it 'wok fried prawn with lemon citrus sauce' because we use about 50 per cent salted egg yolk, 50 per cent lemon juice and curry leaf.'
But others such as Seafood International's chef Pung say: 'Eating salted egg yolk once in a while is fine. After all, if you want to taste good food, you have to sacrifice something.'
» Get in on the yolk
This article was first published in The Sunday Times on Mar 23, 2008.