Key Lime Pie
["4 eggs, separated", "1 (14 oz.) can sweetened condensed milk", "1/3 c. Key lime juice or regular lime juice", "1/2 tsp. cream of tartar", "1/3 c. sugar", "1 baked 9-inch pie crust or graham cracker crust"]
["Combine egg yolks, condensed milk and lime juice in a heavy saucepan.", "Cook over low heat, stirring constantly, until mixture reaches 160\u00b0 (about 10 minutes).", "Beat egg whites and cream of tartar at high speed until foamy.", "Gradually add sugar, 1 tablespoon at a time, beating until stiff peaks form and sugar dissolves (2 to 4 minutes).", "Pour hot filling into pie shell. Immediately spread meringue over filling, sealing to edge.", "Bake at 325\u00b0 for 25 to 30 minutes.", "Cool before serving."]
["eggs", "condensed milk", "lime juice", "cream of tartar", "sugar", "pie crust"]