Combine 1 egg and 3 egg yolks in a medium mixing bowl; beat slightly. Combine 1 cup sugar, brown sugar, flour, and cornmeal, mixing well; add to egg mixture, mixing until smooth. Add butter, milk, vanilla, and vinegar; mix well. Pour filling into pastry shell. Bake at 400° for 10 minutes. Reduce heat to 325°, and continue baking 45 minutes.
Beat egg whites (at room temperature) until foamy; add cream of tartar, beating slightly. Gradually add remaining sugar, 1 tablespoon at a time, beating until stiff peaks form and sugar dissolves. Spread meringue over hot filling, sealing to edge of pastry. Bake at 350° for 10 minutes or until meringue is golden brown.