gravy train

US /ˈɡreɪ.vi treɪn/
UK /ˈɡreɪ.vi treɪn/
"gravy train" picture
1.

a situation in which someone can make a lot of money for very little effort

:
He got on the gravy train when he inherited his uncle's business.
Many people try to get on the gravy train of government contracts.