Preheat the oven to 400°F (200°C)
Rinse and dry the chestnuts
Cut an X-shaped slit on the flat side of each chestnut
Place the chestnuts on a baking sheet with the cut side up
Roast for 20 to 30 minutes until the shells open and the nuts are tender
Remove from the oven and cover with a clean towel for 10 minutes
Peel off the shells and inner skins while still warm
Serve warm