1 (9 inch) prepared graham cracker crust
2 cans sweetened condensed milk
1/2 cup sour cream
3/4 cup key lime juice (not regular lime juice)
Preheat oven to 350 degrees
In a medium bowl, mix all filling ingredients well, then pour into graham cracker crust.
Bake in preheated oven for 5 to 8 minutes, until tiny pinhole bubbles burst on the surface of pie. DO NOT BROWN! Chill pie thoroughly before serving. Garnish with lime slices and whipped cream if desired.