Raw blood soup (tiết canh in Vietnamese) is a dish made with raw blood of ducks or geese , with peanuts and herbs on top, a traditional dish in Vietnamese cuisine.
The freshly drawn blood is collected in a bowl, and prevented from premature coagulation (hãm huyết), by mixing it with some fish sauce of certain proportions, usually three to five soup spoons of fish sauce for one quart of blood. Finely chopped meat such as cooked duck innards (such as gizzards) for almost a shallow dish along with a sprinkling of crushed peanuts and chopped herbs such as Vietnamese coriander, mint, etc. The blood and fish sauce mixture is then diluted with some watery broth left from cooking the meat and/or gizzards to promote blood coagulation, then quickly poured into the prepared meat dish. After the blood has set, the finished dish resembles a pizza. The finished dish can be kept cooled in the refrigerator, which allows the blood to maintain its coagulated state, when immediate consumption is not called for right away. If the dish is removed from the refrigerator and left to sit at room temperature for a while the blood will return to a liquid state