1 (9") graham cracker crumb crust
4 egg yolks, lightly beaten
1 (14 oz.) sweetened condensed milk
2/3 c. key lime juice
1 c. heavy cream, whipped with 3 tbsp. sugar

Beat egg yolks with condensed milk just to blend. Add lime juice. Beat until smooth. Pour into pie shell. Chill several hours or overnight. Beat cream with sugar and spread over pie.