The following passage is from "Chinese Gastronomy", one of the best books on Chinese cuisine I've ever seen. It beautifully expresses the nearly metaphysical regard that the Chinese have for food and eating and is delightful reading even if you never cook a single recipe from it. This dish is incredibly good, considering that its main ingredients are pork fat and skin. The fat is not something to be gotten rid of in this case. It's treasured for what it is. Like I said, this is something that I don't cook often but it's a special occasion when I do.
This is one of my all time favorites. I serve it with a bowl of Chinese mustard and a bowl of chopped green onions for dipping.
At one time the butcher shops of Soochow were variously called Genuine Straw Mat, Original Straw Mat, Old Straw Mat, etc., just because there is a story about an Immortal in disguise who flung a bit of mat into a pot of belly pork to give it a special fragrance. The fragrance is easy enough to produce. What is important is that it stands out in a clear field. Instead of being heavy, the pork should appear light; clean instead of messy; smooth instead of lumpy. The flavor of pork is effusive. While the cooking of chicken and beef means the careful carving out of its best flavor from the raw material, the flavors of pork must be restrained. At its best, pork is tender, sweet, fragrant, tasty, rich without being oily (in other words, nun, hsien, hsiang, nung, yu-er-pu-ni).
A geometrically precise square of belly pork is stewed and then steamed in a little sauce, so that it is served with an absolutely clear layer of melted fat overlying a smooth brown sauce. The surface is a rich brown color, the fat smooth and custard-like, the meat brown and tender. The square of fat was named after Su Tungpo, the poet, for unknown reasons. Perhaps it is just because he would have like it. The square of fat is regarded with much passion, tenderness and expectation.
Second-rate versions of it appear everywhere, differing from the following version by their failure to clear the field for the delicacy of the pork fat which, if prepared accordingly, tastes fresh and clean like fresh (sweet) butter. In order to keep the flavor clear, the meat is first salted to remove the bloody juices, blanched to remove the scum, then stewed very slowly, and finally steamed for hours to tenderize the fat slowly. Inferior versions this are made by stewing pork for a few hours without steaming it... The result is lumpy fat. If the salt rub and blanching are omitted the juice becomes messy and lumpy. The simplicity of appearance, smoothness and clarity of flavor have to be wrested from the manifold flavors of pork.
Tungpo Pork is customarily served at the end of a meal with bowls of rice. People sigh, shout and groan with happiness when they see it.
This is one of the pinnacles of gastronomy, and sums up the application of fat in Chinese cuisine.
Trim pork into a precise square. Wash it and wipe it dry with a towel. Rub it with salt and let it stand for about 2 hours. Discard the blood-tinged liquid.
Bring 5 pints (12 cups) water to a boil and blanch the meat in it. Rinse it free of scum and repeat the blanching with a fresh portion of boiling water. Place the pork skin side up in a pot with a tight-fitting lid, adding soy sauce, wine, spring onions ginger and 2 tablespoons water. Bring to the boil, then reduce the heat to very low and simmer for 2 hours, adding a little more water if necessary. Keep the amount of liquid as small as possible, and do not keep uncovering the pot to see how the pork is progressing. Let it stew in its own juices.
Discard the spring onions and ginger. Place the square skin side down on a dish of soup plate dimensions, add the juices and cover it very closely with foil, cellophane or an overlapping plate. Steam it for 4 hours, until the fat is tender and can be cut with a spoon. Invert the square so that the fat is uppermost, and pour the juices around it carefully.
From "Chinese Gastronomy" by Hsiang Ju Lin and Tsuifeng Lin, First Harvest/HBJ, New York, 1977. Introduction by Lin Yut