Beat the egg yolks in a small bowl; set aside. Coarsely chop chocolate and place in a 2-cup microwave-safe glass measuring cup with a spout. Add the milk. Place the measuring cup, uncovered, in the microwave. Whisking once or twice, cook on medium-high until chocolate is melted and well blended, 2 1/2 to 3 minutes. Remove the cup from microwave and slowly pour chocolate into the reserved egg yolks, whisking constantly. Return mixture to the measuring cup and cook in microwave until heated through, about 1 minute. You may need to rotate the measuring cup if your microwave doesn’t have a carousel. Pour into mugs and serve.