your bread and butter
US /jʊər brɛd ænd ˈbʌtər/
UK /jʊər brɛd ænd ˈbʌtər/

1.
mata pencarian, sumber penghasilan utama
a person's livelihood or main source of income
:
•
Teaching is her bread and butter, but she also writes novels in her free time.
Mengajar adalah mata pencahariannya, tetapi dia juga menulis novel di waktu luangnya.
•
For a journalist, breaking news is their bread and butter.
Bagi seorang jurnalis, berita terkini adalah mata pencarian mereka.