@juliank
The Belgian recepy:

Peel potatoes.

Cut potatoes into something fry shaped. Preferably with a tool to do so if you want to save time, but with a sharp knife works too.

Deep-fry at 160°C until soft throughout.

Let cool to room temperature (even if you want to eat them the same day).

If you want to marinade, do so now (but I wouldn't).

Deep-fry at 180°C until golden brown (and yummy crusted)

Serve and eat.