one 9-inch diameter pie
Old "conchs", Key West natives, repute this recipe for Key Lime Pie,
to be the original recipe for the famous dessert…not the recipe with sweetened condensed milk.
One baked 9-inch diameter pastry pie crust
(favorite recipe or ½ (15-ounce) refrigerated pie crusts (1 crust)
Prepare pastry shell, bake, cool, and set aside.
In a large heavy saucepan, combine the first three filling ingredients, mixing well. Gradually add milk, blending well. Cook, stirring constantly, over moderate heat until the mixture thickens and comes to a full boil; continue boiling for 1 minute, stirring constantly, and then remove from heat and set aside.
In a small bowl, beat the egg yolks at high speed of an electric mixer until thick and light lemon colored. Quickly stir 2/3 cup hot thickened milk custard mixture into the egg yolks, blending well; stir egg yolk/custard mixture into the remaining custard mixture in the saucepan, blending well. Return custard to the range, and cook over moderate heat, stirring constantly, for 3 minutes. Remove from heat and quickly stir in key lime juice, rum, butter, and grated lime peel, blending well.
Spoon filling into the baked pastry shell and chill in the refrigerator for at least four hours.
To prepare meringue, combine egg whites and cream of tartar in a deep medium bowl; beat at high speed of an electric mixer for 1 minute. Gradually beat in the sugar, one tablespoonful at a time, and then the rum; continue beating at high speed until stiff, but not dry, peaks are formed, about 3 to 4 minutes. Spread the meringue in swirls over the top of the lime filling to the edge of the pie, sealing the meringue to the pie. Bake in a preheated moderate oven (350 degrees F.) for 12 to 15 minutes or until meringue is lightly browned. Cool pie thoroughly before cutting into wedges and serving.
Note: If fresh key lime juice is unavailable, may use bottled key lime juice; however, fresh lime juice is preferable.
Variation: Omit meringue and top chilled lime custard filled pie with rum flavored sweetened whipped cream.