Cullen skink is a thick Scottish soup made of smoked haddock, potatoes and onions. An authentic Cullen skink will use finnan haddie, but it may be prepared with any other undyed smoked haddock.

Cullen skink appears in many traditional Scottish cookbooks and appears in numerous restaurants and hotel menus throughout Scotland, the UK, and internationally. In 2012 a Guardian columnist described the dish as "the milky fish soup which has surely replaced your haggises and porridges as Scotland's signature dish".

Skink is a Scots word for a shin, knuckle, or hough of beef, which has developed the secondary meaning of a soup, especially one made from these. The word skink is ultimately derived from the Middle Dutch schenke "shin, hough" (cognate with the English word shank and German Schenkel, 'thigh', and Schinken, 'ham"). It is not to be confused with the skink, a family of lizards belonging to the infraorder Scincomorpha.

Local recipes for Cullen skink have several slight variations, such as the use of milk instead of water or the addition of single cream. Cullen skink was traditionally served with bread. It has been described as "smokier and more assertive than American chowder, heartier than classical French bisque."

More Info: en.m.wikipedia.org