금상첨화가 · 금상첨화를
icing on the cake; one good thing on top of another
Example
음식도 맛있는데 가격까지 싸니 금상첨화예요.
The food is delicious and it's cheap too—that's the icing on the cake.
Word parts
금 brocade+상 on+첨 add+화 flower
Literally 'adding flowers on top of silk brocade.'
Good to know
Its opposite is 설상가상 'frost on snow,' meaning one misfortune piled on another.