To those who are familiar with the usual Chinese salted fish, bacalhau, or salt cod, can look strange
and unappetising - the off-white slabs bear little resemblance to fish.
What is it? Bacalhau is cod that's been salted then dried to preserve it. Because cod are large fish, bacalhau is sold cut into pieces, not whole as with most Chinese salted fish. Bacalhau needs to be soaked - with frequent changes of water - for about 24 hours, or up to several days depending on the size of the piece of the fish and how salty and dry it is.
What to look for: it should be evenly pale, without any yellow or dark spots. The fish should be slightly pliable and not brick-hard. It shouldn't have a strong, fishy odour, and it shouldn't smell of ammonia, which would indicate it wasn't dried properly. Larger pieces tend to be more expensive by weight than small chunks, which probably come from the trimmings.
What else? Bacalhau is traditionally popular in Catholic countries such as Spain, Portugal and France, where it was eaten on fast days (such as Fridays and during Lent).
How to use: after soaking the fish in water to rid it of excess salt, bacalhau can be prepared many ways. Individual portions can be poached in milk or broth and served with sauce; simmered with tomatoes, onions and other flavourings; or baked with potatoes, onions, garlic and olive oil. In the French dish of brandade de morue, soaked, cooked salt cod is emulsified (like a mayonnaise) with lots of garlic and olive oil, cream and (sometimes) cooked potatoes and served as a dip for vegetables and bread.