When Spring Festival is around, the Ha Ni ethic group of Zhenyuan county will kill a pig and make the delicious pig blood "Bai Wang" to entertain relatives and friends. Such custom has been thousands of years in Ha Ni history and the traditional way of making it like this: first put some fried and cold salt in the basin for blood. When the blood is falling into the basin, someone should stir it without stopping till the hot blood turns cold.
Another work is to cut the meat of the pig leg and the live into pieces, string them together with bamboo ropes, boil them in the pot and cut into thin chips, add into some condiments like Chinese prickly ash, pepper, coriander, ground pepper, amomum, tsao-ko peanut powder and salt and stir them again and again. Then pour the cold blood and some cold water into the meat. The last thing is to put some charcoal fire on the basin, covered by a winnowing pan till the food seems like bean-starch jelly.