Lemon Sour Cream Pie

1 cup sugar

3 TBSP corn starch

1 cup milk           

¼ cup lemon juice

3 eggs yolks, slightly beaten           

¼ cup margarine or butter

1 TBSP grated lemon peel           

1 cup sour cream

Combine sugar and corn starch in medium pan.  Stir in milk, lemon juice and egg yolk on medium heat until thick.  Stir constantly.  Remove from heat, add margarine and lemon peel, cool and fold in sour cream.  Pour into baked pie crust and refrigerate.