Method

1. In a small bowl, whisk together the corn flour with 1/4 cup milk until smooth.
2. In a separate, larger bowl, whisk the sugar and cacao together until combined.
3. Pour the remaining 3/4 cup of milk into a small saucepan and place on high heat on the stove. As soon as the milk comes the boil, reduce the heat to low and start whisking in the milk and corn flour mixture.
4. Then add the cacao and sugar mixture slowly while whisking continuously until smooth.
5. Add the chopped chocolate and whisk for for about 3 minutes.
6. Serve immediately.