The most easy way is to microwave.
Cut a "+" on top of each chestnut and put it on a microwavable plate.
12 chestnut @ power level 70%, 3 minutes.
or 80% for 2 minutes. Thenit's ready to eat!!! (my is a 1000kw Sanyo microwave.
If you find it too hard to eat, means your power level is too high and your time too long. Because the microwave power level is all different from one to another, you may need to test a few times before you get the good timing and power level on your microwave.
Also how much chestnuts you microwave at the same time also matters.
Enjoy!