This is the 8762nd most frequent Russian word.
повар
Cook; chef.
Here, 'повар' is used to refer to a professional chef working in a culinary environment.
Повар готовит вкусные блюда для гостей.
The cook prepares delicious dishes for the guests.
In this sentence, 'поваром' is the instrumental case of 'повар' indicating the profession my friend aspires to.
Мой друг мечтает стать известным поваром.
My friend dreams of becoming a famous chef.
The word 'повара' is in the accusative case and denotes the person recently employed at the restaurant.