Beef stroganoff or beef stroganov (uk: , us: ; russian: бефстро́ганов, romanized: befstróganov, ipa: [bʲɪfˈstroɡənəf]) is an originally russian dish of sautéed pieces of beef served in a sauce of mustard and smetana (sour cream). from its origins in mid-19th-century russia, it has become popular around the world, with considerable variation from the original recipe. mushrooms are common in many variants.
Source: Wikipedia