An ancient Chinese cooking technique where food is immersed in an aromatic, soy based stock and gently simmered. Meat cooked in such a fashion is given the name "soy-cooked" or "red-cooked", due to the mahogany colour the stock imparts. Chicken is the most common food that is given the master stock treatment, but pigeon, duck, quail and pork are also often used.
The technique is fairly simple. Water is infused with shaoxing wine, star anise, yellow rock sugar, mandarin peel as well as other aromatics and of course, soy sauce. The key here is to use dark soy sauce as opposed to the light soy sauce that is usually found at your grocery store. Dark soy is far more unctuous and rich than light soy. When you tip a bottle up and down, the neck will be coated with the sauce. More importantly, dark soy is less salty and will not overpower the food cooked in a master stock, it only leaves a deep, wonderful colour.
Each time a new ingredient is cooked in the stock, it imparts its own flavour, but in addition, this ensures the stock's longevity. Every time it is boiled, any microbes and other nasties are killed off. I have heard that some stocks in China are hundreds of years old (mine is a mere 2 years). It is quite comforting to think that some of the cooking you were doing years ago is still imparting flavour today.
If you would like to have a shot yourself, here is a recipe.
750 ml (3 cups) dark soy sauce
750 ml (3 cups) water
250 ml (1 cup) shaoxing wine or dry sherry
1 large knob ginger, sliced
4 star anise
150 gm (1/4 lb) yellow rock sugar
2 cinnamon sticks
2 cloves garlic
4 pieces dried mandarin peel
Basically, just put it all in a pot and simmer for half an hour, then you are ready to cook. Using a whole chicken as an example; wash and dry a size 15 (1.5 kg) chicken (go for free range, they not only taste better, but they lead a much more pleasant life) and place breast down into the stock and simmer for 15 minutes. Turn the chicken over and simmer for a further 15 minutes. Cover the pot and let cool for 45 minutes. Remove the chicken, carve and serve (maybe with rice and greens).
As long as the stock is brought to the boil once a week, it will last in the refrigerator indefinitely. Perhaps for centuries.