In a large saucepan, combine sugar and cornstarch; gradually stir in water until smooth. Bring to a boil; cook and stir for 2 minutes or until thickened. Remove from the heat. Stir in gelatin and lemon juice until gelatin is dissolved. Cool to room temperature.
Prepare pudding mixes according to package directions. Pour into pastry shells. Top with strawberries. Carefully spoon gelatin mixture over berries. Refrigerate until set. Garnish with whipped cream if desired. Yield: 6 pies (8 servings each).