Key Lime Pie

Combine egg yolks, condensed milk and lime juice in a heavy saucepan.

Cook over low heat, stirring constantly, until mixture reaches 160° (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° for 25 to 30 minutes.

Cool before serving.