*available at specialty foods shops and some supermarkets Preheat oven to 250F. and line a baking sheet with parchment or foil. In a bowl with an electric mixer beat egg whites with salt and cream of tartar to soft peaks. Add sugar gradually, beating, and beat meringue to stiff peaks. Beat in vinegar, cornstarch, and vanilla. Onto prepared baking sheet spread meringue with the back of a spoon into 3 1/2- to 4-inch rounds, making them slightly higher around the edges to form shells. Bake meringues in lower third of oven 1 hour, or until crisp on outside but soft in middle. Peel parchment carefully form meringues and cool meringues on a rack. Meringues keep in an airtight container 1 day. Serve meringues topped with sorbet, whipped cream, and kiwis. To make the sorbet: In a small heavy saucepan combine sugar and water and bring to a boil, stirring until sugar is dissolved. Remove pan from heat. in a blender or food processor puree raspberries with Champagne, creme de cassis, and sugar syrup until smooth. Force puree through a fine sieve set over a bowl, pressing hard on solids, and stir in lemon juice. Chill mixture until cold and freeze in an ice-cream maker. Makes about 1 quart. Serves 6. Gourmet March 1994