Sour Cream Lemon Pie

This is a recipe I found on allrecipies.com.  I love the light lemon flavored custard pie.   This had everyone going back for seconds. 

Ingredients:

1 C sugar
1/2 C flour
1/2 t salt
2 C milk
3 egg yolks
1/4 C butter
1/4 C lemon juice
1 1/2 t lemon zest
1/2 C sour cream
1 (9 inch) pie crust baked

Directions:

In a saucepan, combine sugar, flour, and salt. Gradually stir in milk. Cook and stir on medium heat until thickened and bubbly. Reduce heat, and cook and stir 2 more minutes. Remove from heat.

Beat yolks slightly. Gradually stir 1 cup of mix into yolks. Return yolk mixture to saucepan, and bring to gentle boil. Cook and stir 2 more minutes. Remove from heat, and stir in butter, peel, and juice. Fold in sour cream.

Pour filling into baked pie shell, and cool. Top with whipped cream if desired.