Pulse the cocoa nibs in a spice grinder 3 to 4 times until the nibs are coarsely chopped. Place the nibs in a 1-quart microwave-safe measuring cup and add the milk. Microwave on high for 3 to 4 minutes or until the milk reaches 160 degrees F. Steep at room temperature for 30 minutes.
Meanwhile, combine the chocolate, sugar, water and salt in the carafe of a 1-liter French press. Set aside.
After steeping, return the nib-milk mixture to the microwave and heat on high for 2 minutes until it simmers or reaches 185 degrees F. Strain the hot nib-milk mixture through a fine-mesh strainer into the French press carafe. Set aside for 1 minute, and then stir to combine the chocolate and milk. Pump the plunger of the French press 10 to 15 times to froth and aerate. Serve immediately.
Recipe courtesy Alton Brown, 2011