Beat egg yolks in a Dutch oven until thick and lemon colored. Add next 8 ingredients; mix well. Cook over medium heat until thickened. Pour mixture into pastry shell. Sprinkle with nutmeg.
Beat egg whites (at room temperature) and cream of tartar until foamy. Gradually add remaining sugar, one tablespoon at a time, beating until stiff peaks form. Spread over hot filling, sealing to edge of pastry. Bake at 350° for 10 minutes or until golden brown. Cool.