And you can't get much more "open" than a bonfire:
Once the obligatory bonfire was well under way, he produced these goodies, and instructed us to stop feeding it just before lunch break, by which time there would be a good pile of ashes.
The tin was then inserted, and by the time we'd finished our lunch break, the chestnuts were done, and the vultures descended.
Jolly nice they were, too! I can't remember the last time I had real chestnuts, roasted over a real fire: well, I can, it was back when we lived in East Anglia, in a stone-floored bungalow whose only heating was an open fire in the living room. ("Aye lad, we used t'live in't shoe box in't middle o't road...") I can remember being shown by my Nana how to put chestnuts on the small coal shovel, and to put them carefully into the side of the fire. I must have been about ten years old.
But once we moved back to London, it was all Parkrays (enclosed fires inset in the old chimney breasts) with back boilers, and then gas central heating boilers.
Which means that I've never really had the opportunity to roast chestnuts, since then.
So thank you, Bob, for bringing the joy of roasted chestnuts back into my life!
And if any of you out there are thinking about having a go, here are the details:
Buy a bag of chestnuts.
Cut off a corner, or pierce them with a stout skewer (mind your fingers as you do). This prevents them bursting, and jumping out of the fire.
Put a shallow layer into a metal container.
Push metal container - without the lid - into the ashes of a good hot bonfire.
Leave until they are just starting to go black.
When the skins have split, they are ready for eating. Pick off the shells and toss them into the bonfire - then eat the contents.
Once you have finished, don't forget to rescue the tin, clear up any mess, ensure the bonfire is safely extinguished, then pack away the tin ready for the next time.