Prepare the Mocha Mousse. Heat 1-inch of water in the bottom half of a double boiler over medium high heat. Place 14 ounces semisweet chocolate, 4 ounces unsweetened chocolate, 1/2 cup water, 4 tablespoons of instant coffee, and 2 tablespoons cocoa in the top half of the double boiler. Tightly cover the top with film wrap. Heat for 6 to 7 minutes, remove the film wrap, and stir the mixture until smooth. Keep at room temperature until needed.
Place egg whites in the bowl of an electric mixer fitted with a balloon whip. Whisk on high speed until soft peaks form, about 1 minute. Continue to whisk while gradually adding 2 tablespoons of sugar. Whisk until stiff, about 30 seconds.
Whip 3/4 cup heavy cream in a well-chilled stainless-steel bowl until stiff. Fold 1/4 of the egg whites into the melted chocolate mixture, then fold in the whipped cream now fold in the remaining egg whites. Hold the mocha mousse at room temperature.
Recipe courtesy of Trellis Restaurant, Williamsburg, VA