Preheat the oven to 400°F (205°C)
Rinse and dry the chestnuts
Cut an X on the flat side of each chestnut
Place chestnuts cut-side up on a baking sheet
Roast for 20 to 30 minutes
Shake the pan once or twice during roasting
Remove when the shells open and the nuts are tender
Wrap the hot chestnuts in a clean towel for 5 to 10 minutes
Peel off the shells and inner skins while warm