Chocolate Mousse - bittersweet chocolate

Method

• Put the chocolate in a medium heatproof bowl.
• Bring a saucepan filled with 1 inch or so of water to a very slow simmer; set the bowl over, but not touching, the water.
• Stir the chocolate occasionally until melted and smooth.
• (Alternatively, put the chocolate in a medium microwave-safe bowl.
• Melt at 50 percent power in the microwave until soft, about 1 minute.
• Stir, and continue heat until completely melted, about 1 to 2 minutes more.)
• Whip the cream in a medium bowl until it holds soft peaks.
• Take care not to over whip the cream or the mousse will be dense.
• Cover and refrigerate while you cook the eggs.
• Whisk the water and espresso powder together in a small bowl.
• Put the eggs in another bowl that also sets over the water in the saucepan.
• Beat the egg yolks, pinch of salt, and sugar until foamy and light, about 30 seconds.
• Set the bowl over the water and whip with an electric mixer or whisk, moving in a circular motion around the bowl, until the eggs get very fluffy and hot to the touch, about 3 minutes.
• Remove the bowl from the heat and continue beating on high speed until the thick ribbons fall from the beater when lifted out of the bowl, about 5 minutes more.
• Fold in the espresso.
• Fold about a quarter of the eggs into the chocolate to lighten it, then fold in the rest of the egg.
• Finally fold the whipped cream into the chocolate base to make a smooth light mousse.
• Pour the mousse into 4 serving dishes or wine glasses.
• Cover and refrigerate until set, about 1 hour.
• Serve.
• For a dark, double-rich mousse, use all bittersweet chocolate instead of the semisweet, and decrease the cream to 3/4 cup.