Chestnuts go hand in hand with the holidays because December is considered prime time for purchasing them fresh, but the season extends from about September to March. Choose chestnuts that are smooth, blemish-free, and heavy for their size. A good trick is to shake the chestnuts -- if you hear a rattle, they are drying out and not worth purchasing. Because chestnuts dry out quickly, keep them in a cool, dry place and use within a week. Fresh chestnuts should keep for up to a month in the refrigerator and several months in the freezer.
Before roasting, use the tip of a sturdy pairing knife to cut an X on the flat side of each chestnut. This will prevent them from exploding during roasting and makes them easier to peel. Arrange the chestnuts in a single layer in an ungreased baking pan.
Preheat the oven to 425 degrees F. Roast the chestnuts for 15 minutes, tossing once or twice during cooking. The outer shells will start to brown and pull apart at the X. Cool the chestnuts slightly, but peel them while still warm; they get increasingly difficult to peel as they cool.
Roll the peeled chestnuts in a clean kitchen towel to remove the thin, papery inner skins. These skins tend to be bitter.