I may have discovered the simplest and neatest way in the world to melt chocolate. First, I place my cast iron griddle on the stove as a normally would and let it heat up over medium-low heat. While this is heating, I grease my largest cookie sheet and then place it on top of the griddle. My cookie sheet is large enough that it rests on the elevated lip of the griddle, NOT directly on the cooking surface of the griddle.
By resting on the lip of the griddle it creates an air space underneath that acts like the water does in a double boiler. When I put chocolate on it to melt, I am very careful not to put any chocolate on, or very near, the area where the lip of the griddle makes contact with the cookie sheet. I assume it would burn if I did. I cover the first cookie sheet with a second that is the same size, creating a lid.
I let the chocolate melt until it is soft but not liquid. I then took crushed candy candy canes, sprinkled them over the top of the melted chocolate and ran a knife through the mixture to evenly distribute everything. I then removed the cookie sheet from the griddle and placed it on a rack to cool. Don't forget to turn off the griddle at this point, I almost did!
Once the cookie sheet was cooled to room temperature, I placed it in my freezer for about 30 minutes. This causes the edges of the chocolate to lift making it very easy to remove the chocolate from the cookie sheet. Remove from freezer and break into small pieces (I used the handle of a butter knife to do this), place in a fancy serving dish and you have a very elegant dessert with minimal effort and mess.
I tried this with chocolate baking bars meant for melting and semi-sweet chocolate chips. Both work equally well. By using the griddle method I didn't have to worry about condensation getting into the chocolate and messing it up during the melting process which was a definite plus. If candy canes aren't your thing, you can add in whatever you like best instead.