It sounds like they might mean kitchen assistant, but there is not quite enough information to tell which position they mean. Are they expecting a person who has been trained in cooking or not? Is he/she also making the salad?
If the person has no formal kitchen training: kitchen assistant.
With training: Line cook

"A line cook is a cook who supervises a specific area of the kitchen, rather than the kitchen as a whole. The line cook reports to the head cook, who is in charge of overall quality control within the kitchen. The duties of a line cook vary, depending on the type of restaurant he or she is employed at. Levels of training are also variable, since different jobs demand different things from their line cooks." Ref. 1.

"Chef de partie
A chef de partie, also known as a "station chef" or "line cook",[4] is in charge of a particular area of production. In large kitchens, each station chef might have several cooks and/or assistants. In most kitchens however, the station chef is the only worker in that department. Line cooks are often divided into a hierarchy of their own, starting with "first cook", then "second cook", and so on as needed."

"Kitchen assistants (often known as kitchen porters or kitchenhands) are usually kitchen workers who assist with basic tasks, but have had no formal training in cooking. Tasks could include peeling potatoes or washing salad, for example. Smaller kitchens more commonly have kitchen assistants who would be assigned a wide variety of tasks (including washing up) in order to control costs"
Ref. 2.