Heat soup in a double boiler top while separating the eggs. Beat the egg yolks until thick and lemon-colored. Remove the soup pot and add egg yolks, stirring well. Add chicken. Cool slightly. Beat 5 egg whites until very stiff. Fold into egg yolk mixture. Gently turn the batter into a well-buttered souffle dish and bake at 190ºC or 30 minutes.