- 1. Preheat oven to 350°F (175°C). 
- 2. In a mixing bowl, combine flour and butter until crumbly. Add cold water gradually until dough forms. Press into pie dish and bake for 10-12 minutes. Let cool. 
- 3. In a saucepan, combine sugar, cornstarch, and salt. Gradually stir in water. Cook over medium heat, stirring constantly, until mixture thickens and boils. Boil for 1 minute. 
- 4. Remove from heat. Stir in butter, egg yolks, lemon juice, and lemon zest. Return to heat and cook for 2 minutes. Pour into baked pie crust. 
- 5. For meringue, beat egg whites and cream of tartar until soft peaks form. Gradually add sugar, beating until stiff peaks form. Spread over hot filling, sealing edges to crust. 
- 6. Bake for 10-12 minutes or until meringue is golden brown. Cool on a wire rack. Refrigerate before serving.