en un éclair

in a flash

→ en
phrase Rare #46,215
in a flash An idiomatic expression meaning very quickly or in no time. It can be used on its own as an enthusiastic question or exclamation.
FR: Elle a terminé ses devoirs en un éclair.
EN: She finished her homework in a flash.

En un éclair?

In a flash?

— Le Facteur (1994)

Il l'a fini en un éclair.

He finished it in the blink of an eye.

En un éclair!

In a flash!

— L'Arche russe (2002)