3 large egg whites
1/2 cup whole milk
3 tbsp sugar
1/4 tsp instant espresso powder
1 cup bittersweet chocolate chips
Set of white chocolate (or milk chocolate) cup and saucers from CuRious Candy (396 Bleecker Street or 43 E. 78th Street)
In a small saucepan over medium heat, stir together milk, sugar, and espresso powder until the milk is hot, but not boiling, and the sugar is dissolved. Place the chocolate chips in a blender.
Pour the hot milk over the chips and run the blender on high until combined (a few seconds).
Add egg whites and run the blender on high until light (about one minute).
Transfer the mousse to four chocolate cups. The chocolate saucers should be chilled.
Cover with plastic wrap and place in the refrigerator until firm, about 3 hours.