Preheat the oven to 425°F (220°C)
Rinse and dry the chestnuts
Place each chestnut flat-side down on a cutting board
Cut an X into the rounded side of each chestnut
Arrange the chestnuts on a baking sheet with the cut side up
Roast for 20 to 25 minutes
Remove from the oven when the shells peel back
Wrap the hot chestnuts in a clean kitchen towel for 5 to 10 minutes
Peel off the shells and inner skins while still warm