Mix both the types of grated chocolate.
Microwave the cream at Med High for 1 minute.
Remove and pour over the grated chocolate.
Cover it and leave undisturbed for 2 minutes.
Whisk gently.
If chocolate and cream donot form a smooth mixture Micro again for 20-30 seconds.
Add butter.
When cold enough to handle add chocochips and roll into balls.
Cool for 5 minutes in the fridge to set.
Notes
Room temperature chocolate and compound will mix and melt fast as they are already soft.