Preheat oven to 450 degrees F. Prepare pastry and line 9-inch pie plate. Line with double thickness of foil. Bake for 8 minutes; remove foil. Bake for 4 to 6 minutes more or until lightly browned. Cool on rack. Reduce oven temperature to 425 degrees F.
Separate egg yolks from whites; place whites in medium bowl and set aside. In large bowl beat butter with electric mixer until fluffy. Beat in sugar until combined. Beat in egg yolks, lemon peel, lemon juice, flour, and salt until just combined. Add milk; beat until just combined (mixture will be thin and will appear curdled).
Thoroughly wash beaters. In the medium bowl beat egg whites with mixer on medium speed until stiff peaks form (tips stand straight). Fold egg whites into beaten mixture. Transfer mixture to prebaked crust.
Loosely tent top of pie with foil to prevent overbrowning, making sure the foil does not touch the filling. Bake 10 minutes. Reduce heat to 350 degrees F. Bake for 20 to 25 minutes more or until set in the center.
Cool 1 hour on wire rack. Cover and refrigerate 3 hours. To serve, top with Candied Lemon Slices. Makes 8 servings.
Candied Lemon Slices
In large skillet combine sugar and water; bring to boiling. Add lemons, thinly sliced. Simmer gently, uncovered, for 1 to 2 minutes or until just softened. Transfer to a wire rack; cool.