Cold Grapefruit Souffle with Pistachios

Select 5 straight-sided (not sloping) 7-ounce glasses. Cut 5 strips of parchment paper about 4 inches wide and about 1 inch longer than the circumference of a glass. Wrap a parchment paper strip around each glass to form a 2-inch collar, and secure with rubber bands or tape.

Combine grapefruit zest and juice in a small bowl and sprinkle gelatin on top; set aside. With a fork, lightly whisk together 5 egg yolks and 1/2 cup sugar in a medium mixing bowl; discard remaining yolk or reserve for another use.

Heat milk in a medium saucepan over medium heat until almost simmering; milk should make a spitting sound when tilting pan. Remove from heat. Whisk about 1/4 cup hot milk into egg-yolk mixture. A little at a time, whisk egg-yolk mixture back into the hot milk in the pan. Cook over low heat, stirring constantly, until mixture begins to thicken, about 5 minutes. Remove from heat, and stir in gelatin mixture. Transfer to a large bowl, and cool to room temperature.

In the bowl of an electric mixer fitted with the whisk attachment, beat egg whites on high speed until foamy. Add remaining 1/4 cup sugar, beating on high speed until stiff peaks form; fold into cooled custard.

In another clean bowl, whisk cream until consistency of sour cream; gently fold into custard mixture.

Divide mixture among glasses. Refrigerate until souffles are set, at least 6 hours or overnight. Before serving, remove collars, and gently press pistachios, one handful at a time, onto exposed sides of souffles. Or, if not using collars, fill glasses and sprinkle with chopped nuts.