Wow-Wow Sauce (sometimes referred to as Bow wow sauce)[1] is a sauce for which the first known recipe was published by William Kitchiner of London in 1817.
[2] It contains port, wine vinegar, parsley, pickled cucumbers or pickled walnuts, English mustard and mushroom ketchup in a base of beef stock, flour and butter.
A recipe appears in Enquire Within Upon Everything (88th edition, 1894).
[3] It is parodied as a sauce of the same name in the Discworld novels of Terry Pratchett, in which ingredients including sulfur and saltpetre render it highly explosive.
A variant of the above real-world recipe is published in The Discworld Companion[4] and Nanny Ogg's Cookbook.