pan. TOPPING: Combine sugar and cornstarch in saucepan; stir in water and juice. Cook, stirring constantly, until clear and thickened. Beat reserved egg yolk in small bowl. Add small amount of hot mixture to yolk. Return to mixture in saucepan; cook 3 minutes, stirring constantly. Cool slightly. Spoon over cheesecake; chill. Garnish with lemon and lime slices and fresh mint, if desired.