Meatballs, called albondigas or albondiguillas, are little balls of ground (minced) meat -- although "fishballs" are also made -- bound with egg. The culinary texts of Al-Andalus describe them as "very nutritious, easily digested, fortifying and good for underweight people, the elderly and for those with weak stomachs." In the eighteenth century, rather unusual meatballs were made to welcome unexpected guests, using "breast of fowl, codfish, sturgeon or frogs." Albondigas are still very popular and are a common feature on the menus of cheap restaurants and taverns and as a tapa in bars. In Spanish homes there is also an alternative version called a filete ruso, which is gradually being ousted by the ubiquitous hamburger.