This is the best way of perfectly roasting chestnuts and only in 30 minutes. Afterwards peeling is a piece of cake.
With a sharp knife carve chestnuts lengthwise as shown in the photo.
Optionally you can fill a bowl with lukewarm water and place them in for an hour. In this way if there is a chestnut warm inside will come out.
In a baking pan place a sheet of foil and add your chestnuts. Carved side up.
Bake in preheated oven (180°) for twenty minutes.
Once cool you can remove the peel easily.