Five or six at a time will do. Place it on a cutting board and cut it with a sharp knife. Cutting it in half will help it cook faster. The chestnut is similar to the potato when it comes to cooking. This should take between 2-5 minutes, depending on the strength of your microwave. Enjoy these chestnuts plain and bite the nut directly off the shell or scoop it out with a small spoon first.
Grab a handful of chestnuts. Chop each chestnut in half. Cook them in the microwave on the "potato" setting. Serve.