厨师 (chúshī) means 'chef' or 'cook' as a professional title. It combines 厨 (kitchen) with 师 (master, professional). It is used to refer to someone who cooks professionally.
这家餐厅的厨师手艺非常好。
zhè jiā cāntīng de chúshī shǒuyì fēicháng hǎo.
The chef at this restaurant is very skilled.
他从小就想当一名厨师。
tā cóngxiǎo jiù xiǎng dāng yī míng chúshī.
He has wanted to be a chef since he was little.
厨师正在厨房里准备今天的菜。
chúshī zhèngzài chúfáng lǐ zhǔnbèi jīntiān de cài.
The chef is in the kitchen preparing today's dishes.