Coarsely chop the chocolate, and place it in a 2-cup microwave-safe glass measuring cup with a spout. Add the milk.
Place the measuring cup, uncovered, in the microwave. Whisking after 1½ minutes, cook the chocolate at medium-high power (70%) until it is melted, well blended, and heated through, 3 to 4 minutes. (You may need to whisk a second time while it is c