Classic Key Lime Pie

Ingredients:

Beat one egg white stiff in a cold metal bowl.  Fold the beaten egg white into a mixture of four egg yolks, the can of condensed milk, and key lime juice.  Pour the mixture into the pie shell.  Make a meringue topping by beating three egg whites stiff and gradually adding the sugar and cream of tartar.  Spread the meringue on the filling and bake for 350°F until egg whites are golden brown (about 15 min).  Chill 8 hours prior to serving.

Note: cook to the filling to 160°F to help avoid salmonella. 
Variations: skip the meringue topping and substitute a boarder of whipped cream after chilling.  Also, grate the rind from two limes (about 1 teaspoon) and add to the pie filling.