Chocolate Mousse

With a whisk beat the egg yolks and sugar together in a 3-quart porcelain or stainless steel bowl until the mixture is thick, pale yellow and falls back upon itself forming a slowly dissolving ribbon. Beat in the orange liqueur. Then set the bowl over a not-quite-simmering pot of water making sure the bowl is not touching the water and continue to beat for 3-4 minutes until the mixture is foamy and too hot to touch it. Then place it over a bowl of cold water and beat for 3-4 minutes until the mixture is cool and again forms the ribbon. It will have the consistency of mayonnaise.

Melt the chocolate with the coffee over a pot of simmering water (the same way you did above). Once melted, remove from heat and beat in the butter with a wooden spoon a bit at a time, to make a smooth cream. Beat the chocolate into the egg yolks and sugar mixture, then beat in the optional orange peel.

Put the egg whites and salt into a bowl and beat until soft peaks are formed. Then sprinkle on the granulated sugar and beat until stiff peaks are formed. Stir one fourth of the egg white mixture into the chocolate mixture. Then fold in the rest. Turn the mixture into serving dishes, dessert cups, petits pots, etc and refrigerate for at least 2 hours or overnight. Pass the whipped cream separately when serving the mousse. What a magnificent creation!!!

Excerpted from Mastering the Art of French Cooking by Julia Child. Copyright © 1961 by Alfred A. Knopf. Reprinted with permission from the publisher Alfred A. Knopf, a division of Random House, Inc.