I've never heard of chocolate paste (and it doesn't sound very appetizing). Maybe it's a British term? How is it used?
Edited to add -- a quick google search says it is a stage the chocolate goes through in the manufacturing process, between the cacao bean and the finished chocolate. Is there another use of the term that refers to something you would find in an ordinary kitchen?
Chocolate paste is derived from the cocao bean. I have just returned ftom Peru where I had the process explained. I purchased two blocks to take back to Australia and it is the best was have a "hit chocolate "drink. Powdered chocolate is not the best way to make a hot chocolate but I haven't been able to find a stockist in iin Australia yet. One square with hot water or milk and a teaspoon of suga