Simmer a cup or two of water in a small saucepan over medium-low heat. Set a heat-proof bowl on top of the pan, making sure the water doesn’t touch the bottom of the bowl.
Place the chocolate in the bowl and stir until most of the chocolate has melted. Make sure the chocolate doesn’t scorch.
Once most the chocolate has melted, remove the bowl from the saucepan.
Add the tahini to the bowl and whisk in the tahini. Mix until well-blended.
Allow the chocolate to cool, then cover the bowl and place in the refrigerator. Allow the mixture to harden for an hour or two. If you leave it in the fridge longer, it maybe too hard to roll into truffles. If this happens, just allow it soften at room temperature.
Scoop out the mixture by the tablespoonful and roll into 1-inch balls.
Place the coatings in to shallow dishes, and roll the truffles until well coated.
Cover and refrigerate until ready serve.