Preheat the oven at 190C.
Peel the potatoes, then lay a parchment paper sheet on a tray. Fold the paper in half (width wise), then open it up again and add the slices of one of the potatoes on one of the paper halves. Add the salmon fillet on top and season with salt, chilli flakes and garlic thin slices.
Fold the free paper half over the one with the fish and potatoes, then seal up the edges by rolling the bottom edge over the top one starting from one end of the paper until the other one, step by step in small lengths.
Proceed the same way with the remaining parchment paper and ingredients.
Introduce the tray to the oven for 25 minutes at 190C.
Take the tray out, leave to rest for a couple of minutes, then carefully open the papillote pouch, really carefully as all the steam is built up in there and it's still hot.