Preheat the oven to 400°F (200°C)
Rinse and dry the chestnuts
Place each chestnut flat-side down on a cutting board
Cut a shallow X on the rounded side of each chestnut
Arrange the chestnuts in a single layer on a baking sheet
Roast for 20 to 25 minutes
Remove from the oven when the shells curl back at the cuts
Wrap the hot chestnuts in a clean kitchen towel for 5 to 10 minutes
Peel off the shells and inner skins while warm