COMBINE sugar and dry gelatin mix. Beat egg whites in medium bowl with mixer on high speed 5 min. or until soft peaks form. Add sugar mixture, 1 Tbsp. at a time, beating constantly until stiff peaks form. Gently stir in lemon juice and cornstarch until blended.
SPREAD into 8-inch circle on parchment-covered baking sheet.
BAKE 1-1/2 hours. Cool completely.
TRANSFER meringue to plate just before serving; top with remaining ingredients.