Preheat oven to 350°. Lightly grease a 2-quart casserole dish.
Cook the macaroni in boiling water following the package
directions until still somewhat firm. Drain the macaroni; return it to the saucepan. Stir in the butter and egg.
Whisk mustard, salt, and nutmeg with the milk. Stir in 2 1/2 cups of the shredded cheese, the grated onion and the
Pour the macaroni mixture into the prepared casserole dish. Top with the
remaining cheese then sprinkle with the paprika.
Bake the macaroni and cheese casserole in the 350° oven for 35 to 45 minutes or until topping is nicely browned.
Calories per serving: 631
Fat per serving: 34.4g