11 oz. semi-sweet chocolate
3/4 c. butter, broken into pieces
5 egg yolks
8 egg whites
3 1/2 tbsp. sugar

Melt chocolate in double boiler. Remove from heat and add butter; stir with wooden spoon. Allow mixture to cool completely, then stir in yolks, one by one. Beat egg whites until very stiff, adding sugar about half way there. Fold chocolate mixture into whites with spatula until well blended. Chill until very cold.