XO sauce is a spicy seafood sauce from Hong Kong with an umami flavour. It is commonly used in southern Chinese regions such as Guangdong. XO sauce contains flavour intense ingredients such as dried Japanese scallops and prawns, shrimp roe and Chinese cured ham. These concentrated flavours are lightly cooked to bring out their flavours through caramelization. Expensive because of the costly and concentrated ingredients, but actually quite economical a very little goes a long way. Excellent for stir-frying or steaming seafoods, meats, vegetables and noodles.