醬 is sauce.
A 1980s Hong Kong invention (with rival claims as to which restaurant), XO sauce is a thick sauce containing dried seafood, ham, and flavorings such as chili peppers. XO sauce borrows its name from XO (extra old) cognac (popular in Hong Kong), along with the pricing (over a hundred dollars for some jars, although you can pick it up for a more reasonable price at an Asian supermarket), and packaging (often in a fancy box).