It’s fun to serve warm chestnuts to your guests and let them each peel their own. Just provide little bowls for the shells.
Center the oven rack. Preheat the oven to 425°F.
Using a sharp paring knife, carefully cut a 1-inch X shape into the flat side of each chestnut, deep enough to cut through the shell and into the flesh. Arrange the chestnuts cut side up in a baking dish. Bake in the preheated oven for 30-35 minutes, or until the X cut into the shells opens to expose the chestnut flesh.
Set aside for a few minutes until cool enough to handle. Then, using your fingertips, peel off the shell from one chestnut, starting at the X. The inside flesh should be tender-soft; if not, pop the chestnuts back in the oven for another 5 minutes.
Peel the shells from the remaining chestnuts. Using the paring knife, remove the bitter skin. Serve warm or at room temperature.