Marrons from our orchard neighbour.
Every year you can sign up for forest randonées to go chestnut gathering in late October. If you do gather your own, make sure you process them within a few days or you will find a pile of frass and your chestnuts full of exit holes made by insect larvae that have been merrily feeding inside.
Chestnuts are very time consuming and tedious to prepare, with tough rich glossy brown outer skins that come off to reveal not a smooth cream coloured nut, but a wrinkled and creviced object covered in brown wallpaper. It is this inner skin that takes the time and it is very difficult to winkle it out of all the nooks and crannies. You need to accept that a lot of your chestnuts will break in the process.
The method I favour is to slit the outer skin once or twice, then microwave them in batches of 10 - 20 for 2 minutes*. Thoroughly peel them while they are still warm (as hot as your finger tips can stand). They can be eaten at this stage (sweet and floury) or you can candy them by following the instructions here. Once candied they are very sweet, but retain that distinctive grainy floury mouthfeel.
If you can't be bothered with all that, buy ready peeled frozen ones.
*This top tip comes from a friend who overheard it in the marketplace in Preuilly.
A chestnut tree in the forest (in this case a private hunting estate near Yzeures).