Chao Gan [Photo via tuchong.com]

Chao Gan, or stewed liver, evolved from ao gan (stewed pork liver) and ao fei (stir-fried pork lung), both folk foods from the Song Dynasty (960-1279). The cleaned chitterlings are cut into pieces after being boiled in water. They are then stewed in mushroom soup with garlic sauce, chopped spring onion, chopped ginger, and pork liver. Chicken soup and mashed garlic should be added before ready to serve. The soup is a glossy dark red and the pork liver and chitterlings are tender. Chao Gan used to be served with small dumplings, but now there is no particular way to eat it.