Cook the macaroni in a pot of salted boiling water until just tender, drain.
Put the bread crumbs in a mixing bowl, pour the scalded milk over the bread, then add 1½ cups of the cheese, reserving the other ½ cup for the topping. Cover the bowl and let stand until the cheese is melted.
Once the cheese is melted, add the drained macaroni, egg yolks, pimento, melted butter, parsley, onion, and salt. Mix together.
Preheat your oven to 165° C (325° F), get out a 7x11 inch baking pan.
In another mixing bowl, use an electric mixer and beat the egg whites and cream of tartar until stiff peaks form.
Fold whites into the macaroni mixture.
Pour mixture into the baking pan and spread out evenly.
Bake for 50 minutes or until set.
Top with the reserved ½ cup of cheese, return to the oven for a few minutes or until cheese is melted.
Serve and enjoy.