
Place the milk in a saucepan. Heat the milk over medium heat until it's very warm. Do not let it boil.
Chop the bittersweet chocolate into smaller pieces, especially if you're using a block of chocolate, or larger chocolate chips.
Add the chocolate to the warm milk, and whisk to melt the chocolate.
Heat over medium heat, while constantly stirring, until the chocolate is melted and mixed in properly with the milk. The milk should turn a brown color with very little chocolate specks.
The milk should be at a low simmer. Lower the heat if the milk is starting to heat too much. Whisk the hot chocolate frequently to prevent the milk and chocolate from sticking to the bottom of the pot and burning.
Simmer the milk mixture on medium low for about 3 - 5 minutes, until the milk starts to thicken. When the milk is starting to thicken, the French hot chocolate is ready to be served. The time will depend on the size of the pot and your stove.
OPTIONAL - Use a stick blender to blend the hot chocolate drink before serving.
Mix in the salt and sugar to your taste. If you like bittersweet chocolate, you will not need to add any sugar, but you can add sugar to your liking.
Stir in coffee or vanilla extract at this stage, if you'd like to.
Serve in small serving cups such as demitasse cups or cappuccino cups. Or equivalent glasses.
Top with whipped cream or creme fraiche or double cream. Or even marshmallows (homemade vanilla marshmallows are perfect for this creamy hot chocolate).