Cook macaroni to al dente in boiling, salted water and drain.
Sauté onion in a little butter.
Add ground meat and stir until brown.
Add tomato paste, thinned with a little water.
Add salt, pepper, cinnamon and nutmeg. Cook until meat is done.
Melt butter; pour over drained macaroni, mixing carefully.
Spread half of the macaroni on the bottom of a 13 x 9 x 2-inch pan.
Sprinkle half of the grated cheese on top.
Spread entire meat mixture on top.
Cover with remaining macaroni and remaining grated cheese.
Sauce
Boil 3 cups of the milk with 1 1/2 sticks butter.
Add flour to remaining 1 cup milk and blend well.
Add flour mixture to boiling butter and milk. Thicken and cool.
After this has cooled, add 5 beaten eggs, or drop small amounts of the milk mixture into the eggs while stirring constantly. Once the egg mixture gets warm to hot, add the remaining milk.
Pour sauce over the ingredients in the pan. Shake the pan and insert a knife to penetrate thoroughly.