4 eggs, separated
1 can sweetened condensed milk
1/2 c. Key lime juice
6 Tbsp. sugar
1/2 tsp. cream of tartar

Preheat oven to 350°. Beat 4 egg yolks, condensed milk and Key lime juice until thick. Pour into an unbaked pie shell. Bake for 45 minutes.

For Topping: Beat 4 egg whites, sugar and cream of tartar until stiff peaks form. Pour on top of pie shell. Bake in oven until egg whites are golden brown.