Microwave is better than hob as you don’t want to cook the chocolate!
heat the cream (in 30 secs intervals in microwave. Add the small peices of chocolate to the hot cream-gently swirl. Let the heat of the cream melt the chocolate- if necessary, heat slowly and gently and stir gently (avoid going to fast or you will get bubbles..Unless you want aero ganache!
you can use this to cover cakes-like frosting or you can even roll it into balls (when chilled) and serve as truffles!