While the meringue is baking, prepare the chocolate mousse. Heat 1-inch of water in the bottom half of a double boiler over medium heat. Place 6-ounces of semisweet chocolate in the top half of the double boiler. Tightly cover the top with film wrap. Allow the chocolate to melt slowly, about 9 to 10 minutes. Remove from the heat and stir until smooth keep at room temperature until needed.
Place 1 1/2 cups heavy whipping cream in the well-chilled bowl of an electric mixer fitted with a well-chilled balloon whip. Whisk on high speed until peaks form, about 1 minute. Set aside for a few minutes until needed.
Whisk 3 egg whites in a large stainless-steel bowl, until soft peaks form, about 3 minutes. Add 2 tablespoons sugar and continue to whisk until stiff peaks form, about 2 to 2 1/2 minutes. Add a 1/4 of the whipped cream to the chocolate and whisk quickly, vigorously, and thoroughly, then add to the egg whites. Now add the remaining whipped cream. Fold all together gently but thoroughly. Refrigerate the chocolate mousse until needed.
Recipe courtesy of Trellis Restaurant, Williamsburg, VA