Steps

1. Break the chocolate into small pieces. Heat it in a double boiler, stirring continuously until it is nicely melted.
2. Pour the cream into a pan over medium heat and let it heat up. When little bubbles appear on the surface, add it to the chocolate and pour in a drop of mirin and soy.
3. Pour the melted mixture into a bowl and put it in the fridge for at least 2 hours to let it set nicely. Take it out 30 minutes before rolling the truffles and let it warm to room temperature.
4. To form the truffles, dip a teaspoon in hot water and scoop out little balls of chocolate from the mixture. Drop in the matcha and coat them evenly.