1 C graham cracker crumbs
2 T melted butter
1 C sweetened condensed milk
3 eggs
1/2 C key lime Juice
1/4 t cream of tartar
1 C Sugar

Mix crumbs with melted butter and press into pan. Beat egg yolks and sweetened milk, then add lime juice. Beat egg whites slightly, add cream of tartar and beat until stiff, slowly adding sugar. Slowly add lime filling to beaten egg whites, blend. Spoon into pie shell and freeze. Top with whipped cream.

Source: Vivian Griggs