We made this ice cream last week, and it is the best chocolate ice cream I have ever tasted. It is like eating a chocolate bar in cold, creamy form.
I grated a little bit of the chocolate to see what the consistency would be like. It made very, very fine shavings which blew all over the kitchen when a slight breeze picked up. I chopped the rest of the chocolate with a serrated knife, as was suggested here.
The ice cream ended up having tiny discernable bits of chocolate in it, which didn't bother me a bit, but if super-smooth texture is desired, perhaps grating the chocolate would be preferable.