Cut the chestnuts crosswise on the underside and cook in water for about 15 minutes. Then peel, also peel off the white skin well.
Melt 40 g butter, lightly caramelize the sugar, add the chestnuts and turn. Pour in the broth and cook the chestnuts for another 15 minutes. - Remove from the broth and keep warm, greatly reduce the broth.
Cut the Brussels sprouts crosswise on the underside and cook in salted water for 15 to 20 minutes. - Turn in the reduced stock and season with pepper and freshly grated nutmeg.
Put the chestnuts and Brussels sprouts together in a bowl and melt the remaining butter over it.