In a small sauce pan, heat the cream over medium heat until you see steam coming off of the surface.
Note: if you're making Mexican Spiced Christmas Truffles, add the chili to the cream to infuse its flavor into the cream.
While you're waiting for your cream to steam, combine the chocolate chips and your desired flavoring (see note) together in a mixing bowl.
Once the cream has begun to steam, pour it over the chocolate in the bowl (strain the chili pepper if you've steeped it in the cream). Allow the cream to melt the chocolate for 5 minutes, then slowly whisk the ganache until it's smooth.
Allow the chocolate to sit at room temperature, and firm up, for about 1 hour. Stir it occasionally to ensure it stays smooth. If your chocolate gets too stiff to stir, heat it over a double-boiler and start the process again.