Ca kho (simmered fish) in Vietnam can be found into two types kho kho and kho nuoc. Ca kho nuoc (wet simmering) usually uses sea fish such as tuna, salmon, mackerel, garrup, its taste is quite light and it is often cooked with a lot of water that can be used to add flavor to steamed rice or bun (rice noodle). In contrast, Ca kho kho (dry simmering) is saltier and cooked until nearly all of the water in the pot evaporates, it is usually made with fresh water fish such as long-jawed anchovy, carp, goby, mullet and many others.
To make both kinds of Ca kho it is neccessary to prepare the ingredients carefully. First of all, one must make a basic sauce using salt, pepper, nuoc mam (fish sauce), sugar and a little nuoc hang, a liquid made from well-cooked sugar like caramel syrup, which has a bitter taste and dark reddish-brown colour, it is often used to create a sweet, bitter taste and adds a nice colour to dishes. Secondly, the cook can use some vegetables, referred to as phu gia in Vietnamese, such as small slices of ripe pine-apple, tomatoes, starfruit, jack-fruit and several chunks of sugar-cane. Of course, the most important ingredient is fish, fresh fish should be chosen to make the dish more delicious. First the fish scales are removed, then washed carefully using water and vinegar.
After careful preparation, the fish is chopped up into small chunks and mixed with spices and vegetables for about 30 minutes before cooking . Then they are put into a pot, clay pots are often used as it increases the taste of the fish and filled with water and a small cup of tea. The cook lets the fish simmer for several hours depending on the type and size of the fish. During the cooking process, we must pay attention to the level of fire and always keep the level of water higher than the head of the fish by up to 1-2 centimetres. The cook leaves the pot stewing until the fish is well-done and gains a desirable level of water, for Ca kho nuoc we keep quite a lot of water left in the pot but for Ca kho kho there should only be a little water left.
Ca kho is often served with steamed rice or bun and can be kept for up to one week.
