Heat pot with 2 cups of water on low/medium heat. The water should not be boiling, only simmering.
Add a glass bowl over the pot. Add your chocolate and butter in the glass bowl. Stir the chocolate and butter until fully melted.
Take the glass bowl out of the pot and let it cool slightly. Add heavy cream and salt to the chocolate mixture. Whisk until the chocolate is smooth.
Refrigerate the chocolate mixture for at least an hour or until the chocolate has hardened.
Take the chocolate mixture out of the fridge and wait until chocolate softens a little so its easier to scoop the chocolate with a spoon.
Form a small ball (¼ inch) with the chocolate and put in a non-stick surface (parchment paper or foil will do).
Roll the ball in matcha or chopped nuts mixture. For matcha, tap off excess matcha powder after rolling. Note: Chopped nuts don't stick well to the truffle as well as matcha powder. Gently press the nuts to the truffle to make it stick.
Store truffles in a cool place or refrigerator. Hope you enjoy!