I found this Chinese delicacy.
These are 6 preserved duck eggs aka thousand year old or century eggs.
They're preserved by covering the egg in a mixture of clay, ash, salt, lime, and rice straw for several weeks to several months, although modern methods use a brine of salt, calcium hydroxide, and sodium carbonate which does the same but more quickly. The story about using horse's urine is a complete fable ;) It's impossible, since urine can never be alkaline enough.
The peeled egg looks black or very dark brown
When you halve it , you see the white has become solid firm and jello-like transparent brown.
The yolk has turned dark green and creamy and smells strongly of ammonia.
So what does it taste like ?
I ate the first one with a spoon ( I know NO FEAR ) : the white has little taste, but a texture like very firm aspic
the yolk is creamy , a bit salty and the fume of ammonia that evaporates in your mouth would probably turn a lot of people off.
Since I have 6 , I made a dish with tofu , ginger, spring onions and a sauce of soy sauce and sesame oil ( I'll post pics when I make this again )
and this morning I made a Chinese "Old and fresh egg omelet" for which I invented a recipe , as I can't find it on Internet.
Peel and slice a preserved egg from top to bottom. ( This one has a very large yolk)
Whip 3 fresh chicken eggs in a bowl with a dash of oil and water. (Adding a teaspoon of water to an omelet makes it fluffier as the water boils off when poured in the pan )
Heat a very lightly oiled non-stick pan on a medium fire, pour two thirds of the mixture in and turn the fire to low.
Arrange the sliced egg in a decorative way on the omelet.
Tear the fresh leaves of coriander up and put them on top of the eggs.
Cover with the rest of the whipped egg, put a lid on the pan and cook on a low fire for another 4 to 5 minutes
I lightly seasoned the omelet with freshly ground white and black pepper , in order not to mask the taste of the preserved egg.
Eat this with a slice of bread or steamed rice.
Please note my genuine Japanese Furoshiki ( wrapping cloth ) underneath ^_^ .
I used it just for the picture of course , I removed it for eating :)
This dish is enough for two persons ( I ate the whole lot myself , I was hungry this morning )
How healthy is it ? It's no different from fresh eggs.
According to this article from China it has almost the same composition as a fresh egg.
I have 1 reservation : the 3rd method in this article uses lead oxide , which is poisonous. Eggs made with that method should be avoided. The ones I have are made in Europe where lead oxide is illegal, they're OK.