Potatoes with togarashi and wasabi butter "en papillote"

Togarashi powder, or shichimi togarashi, is a Japanese seven-spice powder that packs a flavour punch to noodles, soups, rice and meat dishes. Here, it's used to flavour potatoes that are prepared using the French method of cooking in a folded pouch or parcel with lashings of butter; it's incredibly easy and seals in flavour and moisture.