Belachan or dried prawn paste is a dense mixture of fermented ground prawns with a remarkably strong odour. It is sold in dried blocks that range in colour from caramel to dark brown. It should be roasted before use—either wrapped in foil and dry-roasted in a wok or skillet, or toasted over a gas flame on the end of a fork or back of a spoon—to enhance its flavour and kill bacteria. In some recipes, belachan is ground with the rest of the ingredients in a mortar or blender and then fried in oil without toasting. It is not to be confused with fermented prawn sauce (hay koh) which tastes and smells different—.