In medium saucepan, combine sugar and cornstarch; add water and lemon juice. Over high heat, bring to a boil. Reduce heat; cook and stir until slightly thickened and clear, 4 to 5 minutes. Add gelatin, stir until dissolved. Cool to room temperature. Stir in strawberries; turn into prepared pastry shell. Chill 4 to 6 hours or until set. Serve with whipped cream if desired. Refrigerate leftovers.
