Someone who serves food is called a "waiter" or a "waitress" and sometimes called "staff".
A steward or a stewardess.
That is one of the functions of the stewardess or steward
waiter
soda jerk
A horrible person.
One that serves Chinese food.
maintain homeostasis
That person is a 'flight attendant'
server aka waiter/waitress
A person who serves of his or her own free will is officially called a volunteer.
Their food.
food technologists