Fast foods are those which can be prepared, served, and eaten quickly: probably the most typical fast food is the hamburger, a grilled Patty of ground beef served between the slices of a round roll.

快餐食品是那些能很快做好、快速提供服务和快吃的食品：或许最典型的快餐食品就是汉堡包了，汉堡包是一种烤制的牛肉小馅饼，馅夹在园棍面包片之间。

youdao

The stalls were mysteriously serving beef, not pork, placed between two halves of a round bun.

BBC: Is this the original hamburger?