Filling: Preheat oven to 425°F (220°C). Combine sugar, cornstarch and salt in saucepan. Stir in water gradually. Cook over medium heat, stirring constantly, until mixture thickens. Remove from heat. Whisk egg yolks in medium bowl. Stir small amount of cooked mixture into yolks. Add egg mixture to remaining cooked mixture in saucepan. Bring to boil, stirring constantly. Remove from heat. Stir in lemon juice and butter. Fill baked pie shell with lemon filling.
Meringue: Beat egg whites and lemon juice in large bowl with electric mixer until frothy. Gradually beat in sugar, 1 tbsp (15 mL) at a time, until sugar is dissolved and stiff, glossy peaks form. Spread meringue over filling, sealing to edge of pie shell. Bake in preheated 425°F (220°C) oven until meringue is golden, 4 to 5 minutes.
Tip: Sealing meringue to the edge of the pie shell will prevent meringue from shrinking while it bakes.
Tip: Light 'n Luscious Lemon Pudding: Use Lemon Meringue recipe, omit pie shell. Prepare filling. After stirring in butter, lemon rind and juice, pour filling into large bowl. Place plastic wrap on surface of filling; chill. Prepare meringue. Fold meringue into cooled filling. Makes about 5 cups (1.25 L).
Tip: In recipes where uncooked meringue is folded into a pudding or custard mixture, use fresh eggs that do not have cracks in their shells.