Place milk and chocolate in a small saucepan over medium-low heat and simmer, stirring, until chocolate is melted but not boiling, about 5 minutes.
Pour chocolate mixture into a blender. Cover and hold lid down with a potholder; blend until foamy. Pour into a mug. Break the chile into 2 or 3 pieces, discarding seeds, and drop into the hot chocolate. Drink immediately.
To get the authentic taste, you need to use Mexican chocolate, which contains sugar and cinnamon. It gives the hot chocolate its specific taste. I prefer to use 4 little squares of Rey Margo® chocolate, but it's not as easy to find here. You can also use 1/2 tablet Abuelita® chocolate per serving.
Per Serving: 444 calories;14.8 g fat;
62.5 g carbohydrates;
13.8 g protein;
24 mg cholesterol;
108 mg sodium.