write (someone) a blank check

Translations
дать (кому-то) карт-бланш
The boss practically wrote him a blank check when he approved the project.
Начальник практически дал ему карт-бланш, когда одобрил проект.
Definitions
To give someone complete freedom or unlimited authority to act as they see fit, often with regard to spending money or making decisions, without imposing any restrictions or limitations.
Words
check

noun
чек
write

verb
писать
blank

adjective
пустой