Lok lak

Shaking beef or bo luc lac is a Vietnamese dish that consists of beef sauteed with cucumber, lettuce, tomatoes, red onion, pepper, and soy sauce. The beef is cut into small cubes the size of playing dice (hột lúc lắc) before being sauteed. Beef used to be a luxury ingredient; the dish was therefore mostly served at formal events, such as wedding banquets and anniversaries, although now it has become a common food. Before French colonization, cows were only used for manual labour and were working animals. In the Vietnamese language, bò means "beef" and lúc lắc means "shaken". In Cambodia, shaking beef is known as lok lak or loc lac (Khmer: ឡុកឡាក់) and often considered a national dish even though the dish originated in Vietnam. The original lok lak uses high-quality steak cut into cubes and pan-seared in French butter which stems from Indochina's French colonial past, while a simpler version influenced by Chinese culinary techniques uses cheap cuts of beef and Chinese oyster sauce.

Source: Wikipedia