That's exactly what I'm doing : organic, unsweetened cacao powder and stevia in rice milk; not as refined as Richard's inventive recipes, but delicious nevertheless.
Richard, as I already mentioned, I'm a very naive cook; so, I don't understand very well your explanation about beginning the chocolate bars with breaking chocolate; I thought the initial idea was to avoid the sugar present in chocolate, which apparently could not be done that way. Or am I missing something ?
Marc,
What you would buy is an unsweetened baking chocolate, not a chocolate bar. Which should just be pure alkalized chocolate paste. A lot of times it comes already tempered (shiny) which makes it easier to make into bars. This would be chopped up and melted so that you could add other ingredients, typically sugar. But since you don't want to use sugar, this would be where you add things like stevia, vanilla, maybe some cinnamon or nutmeg, etc...
If what you purchased is already tempered then you would melt 3/4 of it (which de-tempers it) and use the other 1/4 as "seed" once all the other ingredients are in to begin the cool down and tempering process.