Pastry for single-crust pie (9 inches)
1 cup sugar
3 tablespoons plus 1-1/2 teaspoons cornstarch
1 cup whole milk
1/2 cup lemon juice
3 large egg yolks, lightly beaten
1/4 cup butter, cubed
1 tablespoon grated lemon zest
1 cup sour cream
1 cup heavy whipping cream, whipped
Preheat oven to 450°. On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim pastry to 1/2 in. beyond rim of plate; flute edge.
Line unpricked pastry with a double thickness of foil. Fill with pie weights, dried beans or uncooked rice. Bake 8 minutes or until bottom is lightly browned. Remove foil and weights; bake 5-7 minutes longer or until golden brown. Cool on a wire rack.
In a large heavy saucepan, mix sugar and cornstarch. Whisk in milk and lemon juice until smooth. Cook and stir over medium-high heat until thickened and bubbly. Reduce heat to low; cook and stir 2 minutes longer. Remove from heat.
In a small bowl, whisk a small amount of hot mixture into egg yolks; return all to the pan, whisking constantly. Bring to a gentle boil; cook and stir 2 minutes. Remove from heat. Stir in butter and lemon zest. Cool without stirring.
Stir in sour cream. Add filling to crust. Top with whipped cream. Store in the refrigerator.