Add one tablespoon of vegetable oil to a 12-inch skillet over medium heat and cook onion until ten der

Increase heat to medium-high

Add ground sirloin and cook, stirring occasionally, until all pan juices evaporate and meat is browned

Add tomatoes with their liquid, sugar, cinnamon, and 3/4 teaspoon salt, stirring to break up tomatoes

Bring to a boil

Reduce heat to low and simmer for 5 minutes

Meanwhile, cook macaroni until al dente, drain and return to pan

Preheat oven to 350?F

To prepare sauce, add 2 tablespoons of vegetable oil to a 3-quart saucepan over medium heat and stir in flour, nutmeg, and 1 teaspoon salt, until blended

Cook 1 minute

Gradually stir in milk and cook, stirring constantly, until mixture boils and thickens for about 10 minutes

Remove saucepan from heat

In small bowl, beat eggs slightly

Into eggs, beat small amount of the hot milk mixture

Slowly pour egg mixture back into milk mixture, stirring constantly until blended

Stir in meat mixture and 1/4 cup Parmesan into macaroni in pan

Spoon into deep 4-quart casserole

Carefully pour sauce over macaroni mixture

In small bowl, mix bread crumbs with 1/4 cup Parmesan cheese, then sprinkle over sauce

Bake, uncovered, 40 minutes or until hot and custard is set

Let stand 10 minutes for easier serving.