Make a cut with the heel of your knife across the chestnut. Only one cut is needed and not a cross-cut. *See Notes
Place cut chestnuts into a bowl and cover with water. Make sure the nuts are submerged. Leave the nuts to soak for at least 30 minutes.
Preheat your oven to 350° Fahrenheit/ 180° Celsius just before you intend to roast your nuts.
Take your chestnuts out of the water and pat them dry with a clean kitchen cloth.
Spread the nuts over a tray lined with parchment paper.
Roast your chestnuts at 350° Fahrenheit/ 180° Celsius for about 25 minutes or until they are cooked through. *See Notes
Allow your nuts to cool after they have been roasted and peel by removing the shell and the skin surrounding the chestnut.
Enjoy as a snack as is or use further in your food.
We found that one cut across the chestnut is more than enough to roast the chestnuts. We used to cut in a cross but it's not required. Besides we found that cutting in a cross, makes the nuts to turn out more dry You can choose to just cut once or to cut in a cross.
Roasting time might vary. It depends on the size and quality of your chestnuts.