1 1/2 cups water
3 ounces unsweetened baking chocolate
1/3 cup white sugar
1 pinch salt
4 1/2 cups milk
Heat water and chocolate in a saucepan over medium heat, stirring constantly, until chocolate is melted and mixture is smooth, about 5 minutes.
Stir sugar and salt into chocolate mixture. Bring to a boil, reduce heat to low, and simmer, stirring constantly, until sugar is dissolved and flavors combine, about 4 minutes. Pour milk into chocolate mixture and cook until hot. Beat with a whisk until foamy or stir until smooth.