Wash and drain chestnuts. Wipe dry with paper towels.
Melt butter in a large cast iron Dutch oven. Add chestnuts and stir to coat with butter, about 1 minute.
Add coffee beans and stir for 1 to 2 minutes. Cover and allow it to roast on the stove over medium low heat for 5 minutes. Continue to stir chestnuts every 5 minutes for a total time of approximately 15 to 20 minutes depending on the size of the chestnuts. Transfer to a bowl.
When chestnuts are cool enough to handle, wipe each one with a paper towel.
Peel and enjoy while still warm.